chore: fix some comments

Signed-off-by: jimmycathy <clonecode@outlook.com>

src/datetime/mod.rs

@@ -976,7 +976,7 @@ impl DateTime<FixedOffset> {
     ///   [Appendix A.5]
     /// - Single letter 'military' time zone names are parsed as a `-0000` offset.
     ///   They were defined with the wrong sign in RFC 822 and corrected in RFC 2822. But because
-    ///   the meaning is now ambiguous, the standard says they should be be considered as `-0000`
+    ///   the meaning is now ambiguous, the standard says they should be considered as `-0000`
     ///   unless there is out-of-band information confirming their meaning.
     ///   The exception is `Z`, which remains identical to `+0000`.
     ///

src/format/parsed.rs

@@ -93,7 +93,7 @@ use crate::{DateTime, Datelike, TimeDelta, Timelike, Weekday};
 /// # Ok::<(), chrono::ParseError>(())
 /// ```
 ///
-/// The same using chrono's build-in parser for RFC 2822 (the [RFC2822 formatting item]) and
+/// The same using chrono's built-in parser for RFC 2822 (the [RFC2822 formatting item]) and
 /// [`format::parse()`] showing how to inspect a field on failure.
 ///
 /// [RFC2822 formatting item]: crate::format::Fixed::RFC2822

src/naive/time/mod.rs

@@ -95,7 +95,7 @@ mod tests;
 /// Practically speaking, though, by the time of the first leap second on 1972-06-30,
 /// every time zone offset around the world has standardized to the 5-minute alignment.
 ///
-/// ## Date And Time Arithmetics
+/// ## Date And Time Arithmetic
 ///
 /// As a concrete example, let's assume that `03:00:60` and `04:00:60` are leap seconds.
 /// In reality, of course, leap seconds are separated by at least 6 months.