Replace thiserror

Cargo.toml

@@ -17,7 +17,6 @@ chrono = "0.4.39"
 rand = { version = "0.9.0", optional = true }
 regex = "1.11.1"
 serde = { version = "1.0.217", features = ["derive"], default-features = false }
-thiserror = "2.0.11"
 
 [dev-dependencies]
 serde_test = "1.0.176"

src/lib.rs

@@ -68,7 +68,6 @@ use regex::Regex;
 use serde::de::Visitor;
 use serde::Deserialize;
 use serde::Serialize;
-use thiserror::Error;
 
 /// A point in time.
 ///
@@ -425,12 +424,22 @@ impl Debug for Time {
     }
 }
 
-#[derive(Error, Debug, Eq, PartialEq, Clone, Copy)]
+#[derive(Debug, Eq, PartialEq, Clone, Copy)]
 pub enum TimeWindowError {
-    #[error("time window start is after end")]
     StartAfterEnd,
 }
 
+impl Display for TimeWindowError {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let message = match self {
+            Self::StartAfterEnd => "time window start is after end",
+        };
+        write!(f, "{message}")
+    }
+}
+
+impl Error for TimeWindowError {}
+
 /// An interval or range of time: `[start,end)`.
 /// Debug-asserts ensure that start <= end.
 /// If compiled in release mode, the invariant of start <= end is maintained, by