diff --git a/src/lib.rs b/src/lib.rs
index b634d00..6ce32da 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -27,7 +27,11 @@ pub struct Instant(InnerInstant);
 impl Instant {
     #[cfg(target_arch = "wasm32")]
     pub fn now() -> Instant {
-        let stamp = web_sys::window().expect("cannot get window").performance().expect("cannot get performance").now();
+        let stamp = web_sys::window()
+            .expect("cannot get window")
+            .performance()
+            .expect("cannot get performance")
+            .now();
         return Instant(Duration::seconds_f64(stamp / 1_000f64));
     }
 
@@ -55,9 +59,11 @@ impl std::ops::Sub for Instant {
 #[cfg(feature = "local-offset")]
 #[cfg(target_arch = "wasm32")]
 pub fn current_local_offset() -> Result<time::UtcOffset, time::error::IndeterminateOffset> {
-    // get_timezone_offset is in minutes
-    time::UtcOffset::from_whole_seconds((js_sys::Date::new_0().get_timezone_offset() * 60f64) as i32)
-        .map_err(|_| time::error::IndeterminateOffset)
+    // The value returned by `getTimezoneOffset()` is inverted. See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/getTimezoneOffset#negative_values_and_positive_values.
+    time::UtcOffset::from_whole_seconds(
+        (-js_sys::Date::new_0().get_timezone_offset() * 60f64) as i32,
+    )
+    .map_err(|_| time::error::IndeterminateOffset)
 }
 
 #[cfg(feature = "local-offset")]