diff --git a/Cargo.lock b/Cargo.lock
index cadfa67..21c78b4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -58,15 +58,6 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "android_system_properties"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "819e7219dbd41043ac279b19830f2efc897156490d7fd6ea916720117ee66311"
-dependencies = [
- "libc",
-]
-
 [[package]]
 name = "anyhow"
 version = "1.0.66"
@@ -326,21 +317,6 @@ dependencies = [
  "zeroize",
 ]
 
-[[package]]
-name = "chrono"
-version = "0.4.23"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "16b0a3d9ed01224b22057780a37bb8c5dbfe1be8ba48678e7bf57ec4b385411f"
-dependencies = [
- "iana-time-zone",
- "js-sys",
- "num-integer",
- "num-traits",
- "time",
- "wasm-bindgen",
- "winapi",
-]
-
 [[package]]
 name = "cipher"
 version = "0.3.0"
@@ -397,16 +373,6 @@ dependencies = [
  "os_str_bytes",
 ]
 
-[[package]]
-name = "codespan-reporting"
-version = "0.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3538270d33cc669650c4b093848450d380def10c331d38c768e34cac80576e6e"
-dependencies = [
- "termcolor",
- "unicode-width",
-]
-
 [[package]]
 name = "color-eyre"
 version = "0.6.2"
@@ -535,50 +501,6 @@ dependencies = [
  "zeroize",
 ]
 
-[[package]]
-name = "cxx"
-version = "1.0.81"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97abf9f0eca9e52b7f81b945524e76710e6cb2366aead23b7d4fbf72e281f888"
-dependencies = [
- "cc",
- "cxxbridge-flags",
- "cxxbridge-macro",
- "link-cplusplus",
-]
-
-[[package]]
-name = "cxx-build"
-version = "1.0.81"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7cc32cc5fea1d894b77d269ddb9f192110069a8a9c1f1d441195fba90553dea3"
-dependencies = [
- "cc",
- "codespan-reporting",
- "once_cell",
- "proc-macro2",
- "quote",
- "scratch",
- "syn",
-]
-
-[[package]]
-name = "cxxbridge-flags"
-version = "1.0.81"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ca220e4794c934dc6b1207c3b42856ad4c302f2df1712e9f8d2eec5afaacf1f"
-
-[[package]]
-name = "cxxbridge-macro"
-version = "1.0.81"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b846f081361125bfc8dc9d3940c84e1fd83ba54bbca7b17cd29483c828be0704"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "darling"
 version = "0.14.2"
@@ -1135,30 +1057,6 @@ dependencies = [
  "tokio-native-tls",
 ]
 
-[[package]]
-name = "iana-time-zone"
-version = "0.1.53"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "64c122667b287044802d6ce17ee2ddf13207ed924c712de9a66a5814d5b64765"
-dependencies = [
- "android_system_properties",
- "core-foundation-sys",
- "iana-time-zone-haiku",
- "js-sys",
- "wasm-bindgen",
- "winapi",
-]
-
-[[package]]
-name = "iana-time-zone-haiku"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0703ae284fc167426161c2e3f1da3ea71d94b21bedbcc9494e92b28e334e3dca"
-dependencies = [
- "cxx",
- "cxx-build",
-]
-
 [[package]]
 name = "ident_case"
 version = "1.0.1"
@@ -1253,7 +1151,6 @@ checksum = "4217ad341ebadf8d8e724e264f13e593e0648f5b3e94b3896a5df283be015ecc"
 name = "its-matrix-bot"
 version = "0.1.0"
 dependencies = [
- "chrono",
  "clap",
  "color-eyre",
  "matrix-sdk",
@@ -1262,6 +1159,7 @@ dependencies = [
  "serde",
  "spaceapi",
  "thiserror",
+ "time",
  "tokio",
  "toml",
  "tracing",
@@ -1310,15 +1208,6 @@ version = "0.2.137"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc7fcc620a3bff7cdd7a365be3376c97191aeaccc2a603e600951e452615bf89"
 
-[[package]]
-name = "link-cplusplus"
-version = "1.0.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9272ab7b96c9046fbc5bc56c06c117cb639fe2d509df0c421cad82d2915cf369"
-dependencies = [
- "cc",
-]
-
 [[package]]
 name = "lock_api"
 version = "0.4.9"
@@ -1617,25 +1506,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "num-integer"
-version = "0.1.45"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
-dependencies = [
- "autocfg",
- "num-traits",
-]
-
-[[package]]
-name = "num-traits"
-version = "0.2.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
-dependencies = [
- "autocfg",
-]
-
 [[package]]
 name = "num_cpus"
 version = "1.14.0"
@@ -2244,12 +2114,6 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
-[[package]]
-name = "scratch"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c8132065adcfd6e02db789d9285a0deb2f3fcb04002865ab67d5fb103533898"
-
 [[package]]
 name = "security-framework"
 version = "2.7.0"
@@ -2523,15 +2387,20 @@ dependencies = [
 
 [[package]]
 name = "time"
-version = "0.1.44"
+version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6db9e6914ab8b1ae1c260a4ae7a49b6c5611b40328a735b21862567685e73255"
+checksum = "a561bf4617eebd33bca6434b988f39ed798e527f51a1e797d0ee4f61c0a38376"
 dependencies = [
- "libc",
- "wasi 0.10.0+wasi-snapshot-preview1",
- "winapi",
+ "serde",
+ "time-core",
 ]
 
+[[package]]
+name = "time-core"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e153e1f1acaef8acc537e68b44906d2db6436e2b35ac2c6b42640fff91f00fd"
+
 [[package]]
 name = "tinyvec"
 version = "1.6.0"
@@ -2722,12 +2591,6 @@ dependencies = [
  "tinyvec",
 ]
 
-[[package]]
-name = "unicode-width"
-version = "0.1.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0edd1e5b14653f783770bce4a4dabb4a5108a5370a5f5d8cfe8710c361f6c8b"
-
 [[package]]
 name = "unicode-xid"
 version = "0.2.4"
@@ -2840,12 +2703,6 @@ version = "0.9.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
 
-[[package]]
-name = "wasi"
-version = "0.10.0+wasi-snapshot-preview1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a143597ca7c7793eff794def352d41792a93c481eb1042423ff7ff72ba2c31f"
-
 [[package]]
 name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"
diff --git a/Cargo.toml b/Cargo.toml
index 5893e95..0be7161 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,7 +11,6 @@ license = "AGPL-3.0-or-later"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-chrono = "0.4.23"
 clap = { version = "4.0.22", features = ["color", "derive"] }
 matrix-sdk = { version = "0.6.2", features = ["e2e-encryption"] }
 never-say-never = "6.6.666"
@@ -19,6 +18,7 @@ reqwest = { version = "0.11.12", features = ["json"] }
 serde = { version = "1.0.147", features = ["derive"] }
 spaceapi = "0.8.1"
 thiserror = "1.0.37"
+time = "0.3.17"
 tokio = { version = "1.21.2", features = ["full"] }
 toml = "0.5.9"
 url = { version = "2.3.1", features = ["serde"] }
diff --git a/src/bot.rs b/src/bot.rs
index eee0bc0..6465de7 100644
--- a/src/bot.rs
+++ b/src/bot.rs
@@ -5,7 +5,6 @@ use std::{
     time::Duration,
 };
 
-use chrono::{DateTime, TimeZone, Utc};
 use color_eyre::{
     eyre::{eyre, Context},
     Help, Result,
@@ -26,6 +25,7 @@ use matrix_sdk::{
 use never_say_never::Never;
 use reqwest::Url;
 use serde::Deserialize;
+use time::OffsetDateTime;
 use tokio::time::sleep;
 use tracing::{event, instrument, span, Level};
 
@@ -53,7 +53,7 @@ pub struct Config {
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum OpenState {
-    Open { since: DateTime<Utc> },
+    Open { since: OffsetDateTime },
     Closed,
 }
 
@@ -71,12 +71,9 @@ async fn get_open_state(api: &ItsApi) -> Result<OpenState> {
             .ok_or(eyre!("missing `lastchange` field"))?
             .try_into()
             .wrap_err("lastchange timestamp out of i64 range")?;
-        OpenState::Open {
-            since: Utc
-                .timestamp_opt(last_change, 0)
-                .single()
-                .expect("nanos count of 0 produced invalid timestamp"),
-        }
+        let last_change = OffsetDateTime::from_unix_timestamp(last_change)
+            .wrap_err("lastchange timestamp out of range")?;
+        OpenState::Open { since: last_change }
     } else {
         OpenState::Closed
     };