diff --git a/Cargo.toml b/Cargo.toml
index a623603..9b6c584 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,7 +24,7 @@ webpki-roots = "0.26"
 pem = "3.0.3"
 thiserror = "2"
 x509-parser = "0.16"
-chrono = { version = "0.4.24", default-features = false, features = ["clock"] }
+time = "0.3.34"
 async-trait = "0.1.53"
 async-io = "2.3.0"
 tokio = { version= "1.20.1", optional= true }
diff --git a/src/state.rs b/src/state.rs
index a69c30a..d49bf41 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -2,7 +2,6 @@ use crate::acceptor::AcmeAcceptor;
 use crate::acme::{Account, AcmeError, Auth, AuthStatus, Directory, Identifier, Order, OrderStatus, ACME_TLS_ALPN_NAME};
 use crate::{any_ecdsa_type, crypto_provider, AcmeConfig, Incoming, ResolvesServerCertAcme};
 use async_io::Timer;
-use chrono::{DateTime, TimeZone, Utc};
 use core::fmt;
 use futures::future::try_join_all;
 use futures::prelude::*;
@@ -20,6 +19,7 @@ use std::sync::Arc;
 use std::task::{Context, Poll};
 use std::time::Duration;
 use thiserror::Error;
+use time::OffsetDateTime;
 use x509_parser::parse_x509_certificate;
 
 #[allow(clippy::type_complexity)]
@@ -191,7 +191,7 @@ impl<EC: 'static + Debug, EA: 'static + Debug> AcmeState<EC, EA> {
             wait: None,
         }
     }
-    fn parse_cert(pem: &[u8]) -> Result<(CertifiedKey, [DateTime<Utc>; 2]), CertParseError> {
+    fn parse_cert(pem: &[u8]) -> Result<(CertifiedKey, [OffsetDateTime; 2]), CertParseError> {
         let mut pems = pem::parse_many(pem)?;
         if pems.len() < 2 {
             return Err(CertParseError::TooFewPem(pems.len()));
@@ -204,7 +204,7 @@ impl<EC: 'static + Debug, EA: 'static + Debug> AcmeState<EC, EA> {
         let validity = match parse_x509_certificate(&cert_chain[0]) {
             Ok((_, cert)) => {
                 let validity = cert.validity();
-                [validity.not_before, validity.not_after].map(|t| Utc.timestamp_opt(t.timestamp(), 0).earliest().unwrap())
+                [validity.not_before, validity.not_after].map(|t| t.to_datetime())
             }
             Err(err) => return Err(CertParseError::X509(err)),
         };
@@ -224,10 +224,7 @@ impl<EC: 'static + Debug, EA: 'static + Debug> AcmeState<EC, EA> {
             }
         };
         self.resolver.set_cert(Arc::new(cert));
-        let wait_duration = (validity[1] - (validity[1] - validity[0]) / 3 - Utc::now())
-            .max(chrono::Duration::zero())
-            .to_std()
-            .unwrap_or_default();
+        let wait_duration = (validity[1] - (validity[1] - validity[0]) / 3i32 - OffsetDateTime::now_utc()).unsigned_abs();
         self.wait = Some(Timer::after(wait_duration));
         if cached {
             return Ok(EventOk::DeployedCachedCert);