diff --git a/gleam.toml b/gleam.toml
index b8a307c..d162fc5 100644
--- a/gleam.toml
+++ b/gleam.toml
@@ -11,7 +11,7 @@ gleam_stdlib = ">= 0.60.0 and < 1.0.0"
 gleam_json = ">= 3.0.1 and < 4.0.0"
 gleam_http = ">= 4.0.0 and < 5.0.0"
 gleam_httpc = ">= 4.1.1 and < 5.0.0"
-birl = ">= 1.8.0 and < 2.0.0"
+gleam_time = ">= 1.2.0 and < 2.0.0"
 
 [dev-dependencies]
 gleeunit = ">= 1.5.1 and < 2.0.0"
diff --git a/manifest.toml b/manifest.toml
index 3e53fa5..574fa83 100644
--- a/manifest.toml
+++ b/manifest.toml
@@ -2,26 +2,23 @@
 # You typically do not need to edit this file
 
 packages = [
-  { name = "birl", version = "1.8.0", build_tools = ["gleam"], requirements = ["gleam_regexp", "gleam_stdlib", "ranger"], otp_app = "birl", source = "hex", outer_checksum = "2AC7BA26F998E3DFADDB657148BD5DDFE966958AD4D6D6957DD0D22E5B56C400" },
   { name = "dot_env", version = "1.2.0", build_tools = ["gleam"], requirements = ["gleam_stdlib", "simplifile"], otp_app = "dot_env", source = "hex", outer_checksum = "F2B4815F1B5AF8F20A6EADBB393E715C4C35203EBD5BE8200F766EA83A0B18DE" },
   { name = "filepath", version = "1.1.2", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "filepath", source = "hex", outer_checksum = "B06A9AF0BF10E51401D64B98E4B627F1D2E48C154967DA7AF4D0914780A6D40A" },
   { name = "gleam_erlang", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_erlang", source = "hex", outer_checksum = "7E6A5234F927C4B24F8054AB1E4572206C41F9E6D5C6C02273CB7531E7E5CED0" },
   { name = "gleam_http", version = "4.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_http", source = "hex", outer_checksum = "0A62451FC85B98062E0907659D92E6A89F5F3C0FBE4AB8046C99936BF6F91DBC" },
   { name = "gleam_httpc", version = "4.1.1", build_tools = ["gleam"], requirements = ["gleam_erlang", "gleam_http", "gleam_stdlib"], otp_app = "gleam_httpc", source = "hex", outer_checksum = "C670EBD46FC1472AD5F1F74F1D3938D1D0AC1C7531895ED1D4DDCB6F07279F43" },
   { name = "gleam_json", version = "3.0.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_json", source = "hex", outer_checksum = "5BA154440B22D9800955B1AB854282FA37B97F30F409D76B0824D0A60C934188" },
-  { name = "gleam_regexp", version = "1.1.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_regexp", source = "hex", outer_checksum = "9C215C6CA84A5B35BB934A9B61A9A306EC743153BE2B0425A0D032E477B062A9" },
   { name = "gleam_stdlib", version = "0.60.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "621D600BB134BC239CB2537630899817B1A42E60A1D46C5E9F3FAE39F88C800B" },
-  { name = "gleam_yielder", version = "1.1.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_yielder", source = "hex", outer_checksum = "8E4E4ECFA7982859F430C57F549200C7749823C106759F4A19A78AEA6687717A" },
+  { name = "gleam_time", version = "1.2.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_time", source = "hex", outer_checksum = "D71F1AFF7FEB534FF55E5DC58E534E9201BA75A444619788A2E4DEA4EBD87D16" },
   { name = "gleeunit", version = "1.5.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "D33B7736CF0766ED3065F64A1EBB351E72B2E8DE39BAFC8ADA0E35E92A6A934F" },
-  { name = "ranger", version = "1.4.0", build_tools = ["gleam"], requirements = ["gleam_stdlib", "gleam_yielder"], otp_app = "ranger", source = "hex", outer_checksum = "C8988E8F8CDBD3E7F4D8F2E663EF76490390899C2B2885A6432E942495B3E854" },
   { name = "simplifile", version = "2.2.1", build_tools = ["gleam"], requirements = ["filepath", "gleam_stdlib"], otp_app = "simplifile", source = "hex", outer_checksum = "C88E0EE2D509F6D86EB55161D631657675AA7684DAB83822F7E59EB93D9A60E3" },
 ]
 
 [requirements]
-birl = { version = ">= 1.8.0 and < 2.0.0" }
 dot_env = { version = ">= 1.2.0 and < 2.0.0" }
 gleam_http = { version = ">= 4.0.0 and < 5.0.0" }
 gleam_httpc = { version = ">= 4.1.1 and < 5.0.0" }
 gleam_json = { version = ">= 3.0.1 and < 4.0.0" }
 gleam_stdlib = { version = ">= 0.60.0 and < 1.0.0" }
+gleam_time = { version = ">= 1.2.0 and < 2.0.0" }
 gleeunit = { version = ">= 1.5.1 and < 2.0.0" }
diff --git a/src/spacetraders_api.gleam b/src/spacetraders_api.gleam
index 24d17cf..3074859 100644
--- a/src/spacetraders_api.gleam
+++ b/src/spacetraders_api.gleam
@@ -1,9 +1,10 @@
-import birl.{type Time}
 import gleam/dict.{type Dict}
 import gleam/dynamic/decode.{type Decoder}
 import gleam/json
 import gleam/list
 import gleam/option.{type Option}
+import gleam/time/calendar.{type Date}
+import gleam/time/timestamp.{type Timestamp}
 import gleam/uri.{type Uri}
 import spacetraders_models/account.{type Account}
 import spacetraders_models/agent.{type Agent}
@@ -1409,14 +1410,14 @@ fn stats_decoder() -> Decoder(Stats) {
 }
 
 pub type Health {
-  Health(last_market_update: Option(Time))
+  Health(last_market_update: Option(Timestamp))
 }
 
 fn health_decoder() -> Decoder(Health) {
   use last_market_update <- decode.optional_field(
     "lastMarketUpdate",
     option.None,
-    decode.optional(time.datetime_decoder()),
+    decode.optional(time.rfc3339_timestamp_decoder()),
   )
   decode.success(Health(last_market_update:))
 }
@@ -1461,11 +1462,11 @@ fn leaderboards_decoder() -> Decoder(Leaderboards) {
 }
 
 pub type ServerResets {
-  ServerResets(next: Time, frequency: String)
+  ServerResets(next: Timestamp, frequency: String)
 }
 
 fn server_resets_decoder() -> Decoder(ServerResets) {
-  use next <- decode.field("next", time.datetime_decoder())
+  use next <- decode.field("next", time.rfc3339_timestamp_decoder())
   use frequency <- decode.field("frequency", decode.string)
   decode.success(ServerResets(next:, frequency:))
 }
@@ -1500,7 +1501,7 @@ pub type ServerStatus {
   ServerStatus(
     status: String,
     version: String,
-    reset_date: Time,
+    reset_date: Date,
     description: String,
     stats: Stats,
     health: Health,
@@ -1514,7 +1515,7 @@ pub type ServerStatus {
 fn server_status_decoder() -> Decoder(ServerStatus) {
   use status <- decode.field("status", decode.string)
   use version <- decode.field("version", decode.string)
-  use reset_date <- decode.field("resetDate", time.date_decoder())
+  use reset_date <- decode.field("resetDate", time.rfc3339_date_decoder())
   use description <- decode.field("description", decode.string)
   use stats <- decode.field("stats", stats_decoder())
   use health <- decode.field("health", health_decoder())
diff --git a/src/spacetraders_models/account.gleam b/src/spacetraders_models/account.gleam
index 82db3f5..fd04d4b 100644
--- a/src/spacetraders_models/account.gleam
+++ b/src/spacetraders_models/account.gleam
@@ -1,6 +1,6 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
 import gleam/option.{type Option}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/account_id.{type AccountId}
 import spacetraders_sdk/internal/time
 
@@ -9,7 +9,7 @@ pub type Account {
     id: AccountId,
     email: Option(String),
     token: Option(String),
-    created_at: Time,
+    created_at: Timestamp,
   )
 }
 
@@ -25,6 +25,6 @@ pub fn decoder() -> Decoder(Account) {
     option.None,
     decode.optional(decode.string),
   )
-  use created_at <- decode.field("createdAt", time.datetime_decoder())
+  use created_at <- decode.field("createdAt", time.rfc3339_timestamp_decoder())
   decode.success(Account(id:, email:, token:, created_at:))
 }
diff --git a/src/spacetraders_models/agent_event.gleam b/src/spacetraders_models/agent_event.gleam
index 5a0fae7..0b64606 100644
--- a/src/spacetraders_models/agent_event.gleam
+++ b/src/spacetraders_models/agent_event.gleam
@@ -1,7 +1,7 @@
-import birl.{type Time}
 import gleam/dynamic.{type Dynamic}
 import gleam/dynamic/decode.{type Decoder}
 import gleam/option.{type Option}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/agent_event_id.{type AgentEventId}
 import spacetraders_sdk/internal/time
 
@@ -11,7 +11,7 @@ pub type AgentEvent {
     type_: String,
     message: String,
     data: Option(Dynamic),
-    created_at: Time,
+    created_at: Timestamp,
   )
 }
 
@@ -24,6 +24,6 @@ pub fn decoder() -> Decoder(AgentEvent) {
     option.None,
     decode.optional(decode.dynamic),
   )
-  use created_at <- decode.field("createdAt", time.datetime_decoder())
+  use created_at <- decode.field("createdAt", time.rfc3339_timestamp_decoder())
   decode.success(AgentEvent(id:, type_:, message:, data:, created_at:))
 }
diff --git a/src/spacetraders_models/chart.gleam b/src/spacetraders_models/chart.gleam
index a5326b2..9203203 100644
--- a/src/spacetraders_models/chart.gleam
+++ b/src/spacetraders_models/chart.gleam
@@ -1,5 +1,5 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/agent_symbol.{type AgentSymbol}
 import spacetraders_models/waypoint_symbol.{type WaypointSymbol}
 import spacetraders_sdk/internal/time
@@ -8,7 +8,7 @@ pub type Chart {
   Chart(
     waypoint_symbol: WaypointSymbol,
     submitted_by: AgentSymbol,
-    submitted_on: Time,
+    submitted_on: Timestamp,
   )
 }
 
@@ -18,6 +18,9 @@ pub fn decoder() -> Decoder(Chart) {
     waypoint_symbol.decoder(),
   )
   use submitted_by <- decode.field("submittedBy", agent_symbol.decoder())
-  use submitted_on <- decode.field("submittedOn", time.datetime_decoder())
+  use submitted_on <- decode.field(
+    "submittedOn",
+    time.rfc3339_timestamp_decoder(),
+  )
   decode.success(Chart(waypoint_symbol:, submitted_by:, submitted_on:))
 }
diff --git a/src/spacetraders_models/chart_transaction.gleam b/src/spacetraders_models/chart_transaction.gleam
index 2851eb4..8b1fbd5 100644
--- a/src/spacetraders_models/chart_transaction.gleam
+++ b/src/spacetraders_models/chart_transaction.gleam
@@ -1,5 +1,5 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/ship_symbol.{type ShipSymbol}
 import spacetraders_models/waypoint_symbol.{type WaypointSymbol}
 import spacetraders_sdk/internal/time
@@ -9,7 +9,7 @@ pub type ChartTransaction {
     waypoint_symbol: WaypointSymbol,
     ship_symbol: ShipSymbol,
     total_price: Int,
-    timestamp: Time,
+    timestamp: Timestamp,
   )
 }
 
@@ -20,7 +20,7 @@ pub fn decoder() -> Decoder(ChartTransaction) {
   )
   use ship_symbol <- decode.field("shipSymbol", ship_symbol.decoder())
   use total_price <- decode.field("totalPrice", decode.int)
-  use timestamp <- decode.field("timestamp", time.datetime_decoder())
+  use timestamp <- decode.field("timestamp", time.rfc3339_timestamp_decoder())
   decode.success(ChartTransaction(
     waypoint_symbol:,
     ship_symbol:,
diff --git a/src/spacetraders_models/contract.gleam b/src/spacetraders_models/contract.gleam
index 8a537e9..7f6d673 100644
--- a/src/spacetraders_models/contract.gleam
+++ b/src/spacetraders_models/contract.gleam
@@ -1,6 +1,6 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
 import gleam/option.{type Option}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/contract_id.{type ContractId}
 import spacetraders_models/contract_terms.{type ContractTerms}
 import spacetraders_models/contract_type.{type ContractType}
@@ -15,7 +15,7 @@ pub type Contract {
     terms: ContractTerms,
     accepted: Bool,
     fulfilled: Bool,
-    deadline_to_accept: Option(Time),
+    deadline_to_accept: Option(Timestamp),
   )
 }
 
@@ -29,7 +29,7 @@ pub fn decoder() -> Decoder(Contract) {
   use deadline_to_accept <- decode.optional_field(
     "deadlineToAccept",
     option.None,
-    decode.optional(time.datetime_decoder()),
+    decode.optional(time.rfc3339_timestamp_decoder()),
   )
   decode.success(Contract(
     id:,
diff --git a/src/spacetraders_models/contract_terms.gleam b/src/spacetraders_models/contract_terms.gleam
index 202ceb6..1c6a514 100644
--- a/src/spacetraders_models/contract_terms.gleam
+++ b/src/spacetraders_models/contract_terms.gleam
@@ -1,20 +1,20 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
 import gleam/option.{type Option}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/contract_deliver_good.{type ContractDeliverGood}
 import spacetraders_models/contract_payment.{type ContractPayment}
 import spacetraders_sdk/internal/time
 
 pub type ContractTerms {
   ContractTerms(
-    deadline: Time,
+    deadline: Timestamp,
     payment: ContractPayment,
     deliver: Option(List(ContractDeliverGood)),
   )
 }
 
 pub fn decoder() -> Decoder(ContractTerms) {
-  use deadline <- decode.field("deadline", time.datetime_decoder())
+  use deadline <- decode.field("deadline", time.rfc3339_timestamp_decoder())
   use payment <- decode.field("payment", contract_payment.decoder())
   use deliver <- decode.optional_field(
     "deliver",
diff --git a/src/spacetraders_models/cooldown.gleam b/src/spacetraders_models/cooldown.gleam
index fb510f5..85a75bc 100644
--- a/src/spacetraders_models/cooldown.gleam
+++ b/src/spacetraders_models/cooldown.gleam
@@ -1,6 +1,6 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
 import gleam/option.{type Option}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/ship_symbol.{type ShipSymbol}
 import spacetraders_sdk/internal/time
 
@@ -9,7 +9,7 @@ pub type Cooldown {
     ship_symbol: ShipSymbol,
     total_seconds: Int,
     remaining_seconds: Int,
-    expiration: Option(Time),
+    expiration: Option(Timestamp),
   )
 }
 
@@ -20,7 +20,7 @@ pub fn decoder() -> Decoder(Cooldown) {
   use expiration <- decode.optional_field(
     "expiration",
     option.None,
-    decode.optional(time.datetime_decoder()),
+    decode.optional(time.rfc3339_timestamp_decoder()),
   )
   decode.success(Cooldown(
     ship_symbol:,
diff --git a/src/spacetraders_models/market_transaction.gleam b/src/spacetraders_models/market_transaction.gleam
index bf2f735..fc9cd7e 100644
--- a/src/spacetraders_models/market_transaction.gleam
+++ b/src/spacetraders_models/market_transaction.gleam
@@ -1,5 +1,5 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/ship_symbol.{type ShipSymbol}
 import spacetraders_models/trade_symbol.{type TradeSymbol}
 import spacetraders_models/transaction_type.{type TransactionType}
@@ -15,7 +15,7 @@ pub type MarketTransaction {
     units: Int,
     price_per_unit: Int,
     total_price: Int,
-    timestamp: Time,
+    timestamp: Timestamp,
   )
 }
 
@@ -30,7 +30,7 @@ pub fn decoder() -> Decoder(MarketTransaction) {
   use units <- decode.field("units", decode.int)
   use price_per_unit <- decode.field("pricePerUnit", decode.int)
   use total_price <- decode.field("totalPrice", decode.int)
-  use timestamp <- decode.field("timestamp", time.datetime_decoder())
+  use timestamp <- decode.field("timestamp", time.rfc3339_timestamp_decoder())
   decode.success(MarketTransaction(
     waypoint_symbol:,
     ship_symbol:,
diff --git a/src/spacetraders_models/repair_transaction.gleam b/src/spacetraders_models/repair_transaction.gleam
index dcc42e7..4dcb633 100644
--- a/src/spacetraders_models/repair_transaction.gleam
+++ b/src/spacetraders_models/repair_transaction.gleam
@@ -1,5 +1,5 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/ship_symbol.{type ShipSymbol}
 import spacetraders_models/waypoint_symbol.{type WaypointSymbol}
 import spacetraders_sdk/internal/time
@@ -9,7 +9,7 @@ pub type RepairTransaction {
     waypoint_symbol: WaypointSymbol,
     ship_symbol: ShipSymbol,
     total_price: Int,
-    timestamp: Time,
+    timestamp: Timestamp,
   )
 }
 
@@ -20,7 +20,7 @@ pub fn decoder() -> Decoder(RepairTransaction) {
   )
   use ship_symbol <- decode.field("shipSymbol", ship_symbol.decoder())
   use total_price <- decode.field("totalPrice", decode.int)
-  use timestamp <- decode.field("timestamp", time.datetime_decoder())
+  use timestamp <- decode.field("timestamp", time.rfc3339_timestamp_decoder())
   decode.success(RepairTransaction(
     waypoint_symbol:,
     ship_symbol:,
diff --git a/src/spacetraders_models/scrap_transaction.gleam b/src/spacetraders_models/scrap_transaction.gleam
index 76dfb35..5d35ee1 100644
--- a/src/spacetraders_models/scrap_transaction.gleam
+++ b/src/spacetraders_models/scrap_transaction.gleam
@@ -1,5 +1,5 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/ship_symbol.{type ShipSymbol}
 import spacetraders_models/waypoint_symbol.{type WaypointSymbol}
 import spacetraders_sdk/internal/time
@@ -9,7 +9,7 @@ pub type ScrapTransaction {
     waypoint_symbol: WaypointSymbol,
     ship_symbol: ShipSymbol,
     total_price: Int,
-    timestamp: Time,
+    timestamp: Timestamp,
   )
 }
 
@@ -20,7 +20,7 @@ pub fn decoder() -> Decoder(ScrapTransaction) {
   )
   use ship_symbol <- decode.field("shipSymbol", ship_symbol.decoder())
   use total_price <- decode.field("totalPrice", decode.int)
-  use timestamp <- decode.field("timestamp", time.datetime_decoder())
+  use timestamp <- decode.field("timestamp", time.rfc3339_timestamp_decoder())
   decode.success(ScrapTransaction(
     waypoint_symbol:,
     ship_symbol:,
diff --git a/src/spacetraders_models/ship_fuel_consumed.gleam b/src/spacetraders_models/ship_fuel_consumed.gleam
index 7ca00be..21807d8 100644
--- a/src/spacetraders_models/ship_fuel_consumed.gleam
+++ b/src/spacetraders_models/ship_fuel_consumed.gleam
@@ -1,13 +1,13 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_sdk/internal/time
 
 pub type ShipFuelConsumed {
-  ShipFuelConsumed(amount: Int, timestamp: Time)
+  ShipFuelConsumed(amount: Int, timestamp: Timestamp)
 }
 
 pub fn decoder() -> Decoder(ShipFuelConsumed) {
   use amount <- decode.field("amount", decode.int)
-  use timestamp <- decode.field("timestamp", time.datetime_decoder())
+  use timestamp <- decode.field("timestamp", time.rfc3339_timestamp_decoder())
   decode.success(ShipFuelConsumed(amount:, timestamp:))
 }
diff --git a/src/spacetraders_models/ship_modification_transaction.gleam b/src/spacetraders_models/ship_modification_transaction.gleam
index 0438405..2e4fc96 100644
--- a/src/spacetraders_models/ship_modification_transaction.gleam
+++ b/src/spacetraders_models/ship_modification_transaction.gleam
@@ -1,5 +1,5 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/ship_symbol.{type ShipSymbol}
 import spacetraders_models/trade_symbol.{type TradeSymbol}
 import spacetraders_models/waypoint_symbol.{type WaypointSymbol}
@@ -11,7 +11,7 @@ pub type ShipModificationTransaction {
     ship_symbol: ShipSymbol,
     trade_symbol: TradeSymbol,
     total_price: Int,
-    timestamp: Time,
+    timestamp: Timestamp,
   )
 }
 
@@ -23,7 +23,7 @@ pub fn decoder() -> Decoder(ShipModificationTransaction) {
   use ship_symbol <- decode.field("shipSymbol", ship_symbol.decoder())
   use trade_symbol <- decode.field("tradeSymbol", trade_symbol.decoder())
   use total_price <- decode.field("totalPrice", decode.int)
-  use timestamp <- decode.field("timestamp", time.datetime_decoder())
+  use timestamp <- decode.field("timestamp", time.rfc3339_timestamp_decoder())
   decode.success(ShipModificationTransaction(
     waypoint_symbol:,
     ship_symbol:,
diff --git a/src/spacetraders_models/ship_nav_route.gleam b/src/spacetraders_models/ship_nav_route.gleam
index 36571c4..7fb9b90 100644
--- a/src/spacetraders_models/ship_nav_route.gleam
+++ b/src/spacetraders_models/ship_nav_route.gleam
@@ -1,5 +1,5 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/ship_nav_route_waypoint.{type ShipNavRouteWaypoint}
 import spacetraders_sdk/internal/time
 
@@ -7,8 +7,8 @@ pub type ShipNavRoute {
   ShipNavRoute(
     destination: ShipNavRouteWaypoint,
     origin: ShipNavRouteWaypoint,
-    departure_time: Time,
-    arrival: Time,
+    departure_time: Timestamp,
+    arrival: Timestamp,
   )
 }
 
@@ -18,7 +18,10 @@ pub fn decoder() -> Decoder(ShipNavRoute) {
     ship_nav_route_waypoint.decoder(),
   )
   use origin <- decode.field("origin", ship_nav_route_waypoint.decoder())
-  use departure_time <- decode.field("departureTime", time.datetime_decoder())
-  use arrival <- decode.field("arrival", time.datetime_decoder())
+  use departure_time <- decode.field(
+    "departureTime",
+    time.rfc3339_timestamp_decoder(),
+  )
+  use arrival <- decode.field("arrival", time.rfc3339_timestamp_decoder())
   decode.success(ShipNavRoute(destination:, origin:, departure_time:, arrival:))
 }
diff --git a/src/spacetraders_models/shipyard_transaction.gleam b/src/spacetraders_models/shipyard_transaction.gleam
index 0d82b7f..b34b708 100644
--- a/src/spacetraders_models/shipyard_transaction.gleam
+++ b/src/spacetraders_models/shipyard_transaction.gleam
@@ -1,5 +1,5 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/agent_symbol.{type AgentSymbol}
 import spacetraders_models/ship_type.{type ShipType}
 import spacetraders_models/waypoint_symbol.{type WaypointSymbol}
@@ -11,7 +11,7 @@ pub type ShipyardTransaction {
     ship_type: ShipType,
     price: Int,
     agent_symbol: AgentSymbol,
-    timestamp: Time,
+    timestamp: Timestamp,
   )
 }
 
@@ -23,7 +23,7 @@ pub fn decoder() -> Decoder(ShipyardTransaction) {
   use ship_type <- decode.field("shipType", ship_type.decoder())
   use price <- decode.field("price", decode.int)
   use agent_symbol <- decode.field("agentSymbol", agent_symbol.decoder())
-  use timestamp <- decode.field("timestamp", time.datetime_decoder())
+  use timestamp <- decode.field("timestamp", time.rfc3339_timestamp_decoder())
   decode.success(ShipyardTransaction(
     waypoint_symbol:,
     ship_type:,
diff --git a/src/spacetraders_models/survey.gleam b/src/spacetraders_models/survey.gleam
index 64be72c..a80c0ad 100644
--- a/src/spacetraders_models/survey.gleam
+++ b/src/spacetraders_models/survey.gleam
@@ -1,6 +1,7 @@
-import birl.{type Time}
 import gleam/dynamic/decode.{type Decoder}
 import gleam/json.{type Json}
+import gleam/time/calendar
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_models/survey_deposit.{type SurveyDeposit}
 import spacetraders_models/survey_signature.{type SurveySignature}
 import spacetraders_models/survey_size.{type SurveySize}
@@ -12,7 +13,7 @@ pub type Survey {
     signature: SurveySignature,
     symbol: WaypointSymbol,
     deposits: List(SurveyDeposit),
-    expiration: Time,
+    expiration: Timestamp,
     size: SurveySize,
   )
 }
@@ -24,7 +25,7 @@ pub fn decoder() -> Decoder(Survey) {
     "deposits",
     decode.list(survey_deposit.decoder()),
   )
-  use expiration <- decode.field("expiration", time.datetime_decoder())
+  use expiration <- decode.field("expiration", time.rfc3339_timestamp_decoder())
   use size <- decode.field("size", survey_size.decoder())
   decode.success(Survey(signature:, symbol:, deposits:, expiration:, size:))
 }
@@ -34,7 +35,10 @@ pub fn encode(survey: Survey) -> Json {
     #("signature", survey_signature.encode(survey.signature)),
     #("symbol", waypoint_symbol.encode(survey.symbol)),
     #("deposits", json.array(survey.deposits, survey_deposit.encode)),
-    #("expiration", json.string(birl.to_iso8601(survey.expiration))),
+    #(
+      "expiration",
+      json.string(timestamp.to_rfc3339(survey.expiration, calendar.utc_offset)),
+    ),
     #("size", survey_size.encode(survey.size)),
   ])
 }
diff --git a/src/spacetraders_sdk/internal/jwt.gleam b/src/spacetraders_sdk/internal/jwt.gleam
index 94d36eb..2474619 100644
--- a/src/spacetraders_sdk/internal/jwt.gleam
+++ b/src/spacetraders_sdk/internal/jwt.gleam
@@ -1,10 +1,11 @@
-import birl.{type Time}
 import gleam/bit_array
 import gleam/dynamic/decode.{type Decoder}
 import gleam/json
 import gleam/option.{type Option}
 import gleam/result
 import gleam/string
+import gleam/time/calendar.{type Date}
+import gleam/time/timestamp.{type Timestamp}
 import spacetraders_sdk/internal/time
 
 pub type JwtDecodeError {
@@ -78,8 +79,8 @@ pub type JwtPayload {
   JwtPayload(
     identifier: String,
     version: String,
-    reset_date: Option(Time),
-    issued_at: Time,
+    reset_date: Option(Date),
+    issued_at: Timestamp,
     subject: String,
   )
 }
@@ -90,10 +91,10 @@ fn jwt_payload_decoder() -> Decoder(JwtPayload) {
   use reset_date <- decode.optional_field(
     "reset_date",
     option.None,
-    decode.optional(time.date_decoder()),
+    decode.optional(time.rfc3339_date_decoder()),
   )
   use issued_at_int <- decode.field("iat", decode.int)
-  let issued_at = birl.from_unix(issued_at_int)
+  let issued_at = timestamp.from_unix_seconds(issued_at_int)
   use subject <- decode.field("sub", decode.string)
   decode.success(JwtPayload(
     identifier:,
diff --git a/src/spacetraders_sdk/internal/time.gleam b/src/spacetraders_sdk/internal/time.gleam
index 43bf3ea..13ec656 100644
--- a/src/spacetraders_sdk/internal/time.gleam
+++ b/src/spacetraders_sdk/internal/time.gleam
@@ -1,18 +1,219 @@
-import birl.{type Time}
+import gleam/bit_array
 import gleam/dynamic/decode.{type Decoder}
+import gleam/pair
+import gleam/result
+import gleam/time/calendar.{
+  type Date, type Month, type TimeOfDay, April, August, Date, December, February,
+  January, July, June, March, May, November, October, September, TimeOfDay,
+}
+import gleam/time/timestamp.{type Timestamp}
 
-pub fn datetime_decoder() -> Decoder(Time) {
+pub fn rfc3339_timestamp_decoder() -> Decoder(Timestamp) {
   use value <- decode.then(decode.string)
-  case birl.parse(value) {
-    Ok(time) -> decode.success(time)
-    Error(Nil) -> decode.failure(birl.now(), "DateTime")
+  case timestamp.parse_rfc3339(value) {
+    Ok(timestamp) -> decode.success(timestamp)
+    Error(Nil) -> decode.failure(timestamp.from_unix_seconds(0), "Timestamp")
   }
 }
 
-pub fn date_decoder() -> Decoder(Time) {
+pub fn parse_rfc3339_date(input: String) -> Result(Date, Nil) {
+  let bytes = bit_array.from_string(input)
+  use #(year, bytes) <- result.try(parse_year(from: bytes))
+  use bytes <- result.try(accept_byte(from: bytes, value: byte_minus))
+  use #(month, bytes) <- result.try(parse_month_calendar(from: bytes))
+  use bytes <- result.try(accept_byte(from: bytes, value: byte_minus))
+  use #(day, bytes) <- result.try(parse_day_calendar(from: bytes, year:, month:))
+  use Nil <- result.try(accept_empty(bytes))
+  Ok(Date(year:, month:, day:))
+}
+
+pub fn rfc3339_date_decoder() -> Decoder(Date) {
   use value <- decode.then(decode.string)
-  case birl.from_naive(value) {
-    Ok(time) -> decode.success(time)
-    Error(Nil) -> decode.failure(birl.now(), "Date")
+  case parse_rfc3339_date(value) {
+    Ok(date) -> decode.success(date)
+    Error(Nil) -> decode.failure(Date(1970, January, 1), "Date")
+  }
+}
+
+pub fn parse_rfc3339_time_of_day(input: String) -> Result(TimeOfDay, Nil) {
+  let bytes = bit_array.from_string(input)
+  use #(hours, bytes) <- result.try(parse_hours(from: bytes))
+  use bytes <- result.try(accept_byte(from: bytes, value: byte_colon))
+  use #(minutes, bytes) <- result.try(parse_minutes(from: bytes))
+  use bytes <- result.try(accept_byte(from: bytes, value: byte_colon))
+  use #(seconds, bytes) <- result.try(parse_seconds(from: bytes))
+  use #(nanoseconds, bytes) <- result.try(parse_second_fraction_as_nanoseconds(
+    from: bytes,
+  ))
+  use Nil <- result.try(accept_empty(bytes))
+  Ok(TimeOfDay(hours:, minutes:, seconds:, nanoseconds:))
+}
+
+pub fn rfc3339_time_of_day_decoder() -> Decoder(TimeOfDay) {
+  use value <- decode.then(decode.string)
+  case parse_rfc3339_time_of_day(value) {
+    Ok(date) -> decode.success(date)
+    Error(Nil) -> decode.failure(TimeOfDay(0, 0, 0, 0), "TimeOfDay")
+  }
+}
+
+const byte_zero: Int = 0x30
+
+const byte_nine: Int = 0x39
+
+const byte_colon: Int = 0x3A
+
+const byte_minus: Int = 0x2D
+
+const nanoseconds_per_second: Int = 1_000_000_000
+
+fn accept_byte(from bytes: BitArray, value value: Int) -> Result(BitArray, Nil) {
+  case bytes {
+    <<byte, remaining_bytes:bytes>> if byte == value -> Ok(remaining_bytes)
+    _ -> Error(Nil)
+  }
+}
+
+fn accept_empty(from bytes: BitArray) -> Result(Nil, Nil) {
+  case bytes {
+    <<>> -> Ok(Nil)
+    _ -> Error(Nil)
+  }
+}
+
+fn parse_digits(
+  from bytes: BitArray,
+  count count: Int,
+) -> Result(#(Int, BitArray), Nil) {
+  do_parse_digits(from: bytes, count:, acc: 0, k: 0)
+}
+
+fn do_parse_digits(
+  from bytes: BitArray,
+  count count: Int,
+  acc acc: Int,
+  k k: Int,
+) -> Result(#(Int, BitArray), Nil) {
+  case bytes {
+    _ if k >= count -> Ok(#(acc, bytes))
+    <<byte, remaining_bytes:bytes>> if byte_zero <= byte && byte <= byte_nine ->
+      do_parse_digits(
+        from: remaining_bytes,
+        count:,
+        acc: acc * 10 + { byte - 0x30 },
+        k: k + 1,
+      )
+    _ -> Error(Nil)
+  }
+}
+
+fn parse_year(from bytes: BitArray) -> Result(#(Int, BitArray), Nil) {
+  parse_digits(from: bytes, count: 4)
+}
+
+// slightly modified version of parse_month that returns calendar.Month instead of Int
+fn parse_month_calendar(from bytes: BitArray) -> Result(#(Month, BitArray), Nil) {
+  use #(month, bytes) <- result.try(parse_digits(from: bytes, count: 2))
+  calendar.month_from_int(month) |> result.map(pair.new(_, bytes))
+}
+
+// slightly modified version of parse_day that takes calendar.Month instead of Int
+fn parse_day_calendar(
+  from bytes: BitArray,
+  year year: Int,
+  month month: Month,
+) -> Result(#(Int, BitArray), Nil) {
+  use #(day, bytes) <- result.try(parse_digits(from: bytes, count: 2))
+  let max_day = case month {
+    January | March | May | July | August | October | December -> 31
+    April | June | September | November -> 30
+    February -> {
+      case is_leap_year(year) {
+        True -> 29
+        False -> 28
+      }
+    }
+  }
+  case 1 <= day && day <= max_day {
+    True -> Ok(#(day, bytes))
+    False -> Error(Nil)
+  }
+}
+
+fn is_leap_year(year: Int) -> Bool {
+  year % 4 == 0 && { year % 100 != 0 || year % 400 == 0 }
+}
+
+fn parse_hours(from bytes: BitArray) -> Result(#(Int, BitArray), Nil) {
+  use #(hours, bytes) <- result.try(parse_digits(from: bytes, count: 2))
+  case 0 <= hours && hours <= 23 {
+    True -> Ok(#(hours, bytes))
+    False -> Error(Nil)
+  }
+}
+
+fn parse_minutes(from bytes: BitArray) -> Result(#(Int, BitArray), Nil) {
+  use #(minutes, bytes) <- result.try(parse_digits(from: bytes, count: 2))
+  case 0 <= minutes && minutes <= 59 {
+    True -> Ok(#(minutes, bytes))
+    False -> Error(Nil)
+  }
+}
+
+fn parse_seconds(from bytes: BitArray) -> Result(#(Int, BitArray), Nil) {
+  use #(seconds, bytes) <- result.try(parse_digits(from: bytes, count: 2))
+  case 0 <= seconds && seconds <= 60 {
+    True -> Ok(#(seconds, bytes))
+    False -> Error(Nil)
+  }
+}
+
+fn parse_second_fraction_as_nanoseconds(from bytes: BitArray) {
+  case bytes {
+    <<".", byte, remaining_bytes:bytes>>
+      if byte_zero <= byte && byte <= byte_nine
+    -> {
+      do_parse_second_fraction_as_nanoseconds(
+        from: <<byte, remaining_bytes:bits>>,
+        acc: 0,
+        power: nanoseconds_per_second,
+      )
+    }
+    <<".", _:bytes>> -> Error(Nil)
+    _ -> Ok(#(0, bytes))
+  }
+}
+
+fn do_parse_second_fraction_as_nanoseconds(
+  from bytes: BitArray,
+  acc acc: Int,
+  power power: Int,
+) -> Result(#(Int, BitArray), a) {
+  // Each digit place to the left in the fractional second is 10x fewer
+  // nanoseconds.
+  let power = power / 10
+
+  case bytes {
+    <<byte, remaining_bytes:bytes>>
+      if byte_zero <= byte && byte <= byte_nine && power < 1
+    -> {
+      // We already have the max precision for nanoseconds. Truncate any
+      // remaining digits.
+      do_parse_second_fraction_as_nanoseconds(
+        from: remaining_bytes,
+        acc:,
+        power:,
+      )
+    }
+    <<byte, remaining_bytes:bytes>> if byte_zero <= byte && byte <= byte_nine -> {
+      // We have not yet reached the precision limit. Parse the next digit.
+      let digit = byte - 0x30
+      do_parse_second_fraction_as_nanoseconds(
+        from: remaining_bytes,
+        acc: acc + digit * power,
+        power:,
+      )
+    }
+    _ -> Ok(#(acc, bytes))
   }
 }