From 3147b942412966fca5791c6dee870ca7d16e8027 Mon Sep 17 00:00:00 2001
From: youdie006 <youdie006@users.noreply.github.com>
Date: Tue, 27 Oct 2026 23:12:18 +0900
Subject: [PATCH] fix(date): accept a period after abbreviated month names

#334 let weekday names take an abbreviating dot (mon., tue.), but
literal_month still parsed only alpha1, so jan. 5 2024 or 14-nov.-2022
were rejected, although the module doc quotes the GNU manual allowing
"an abbreviating dot" and GNU date accepts them.
---
 src/items/date.rs | 31 ++++++++++++++++++-------------
 src/items/mod.rs  | 24 ++++++++++++------------
 src/lib.rs        | 18 ++++++++++++++++++
 3 files changed, 48 insertions(+), 25 deletions(-)

diff --git a/src/items/date.rs b/src/items/date.rs
index 2ff8333..6491396 100644
--- a/src/items/date.rs
+++ b/src/items/date.rs
@@ -268,21 +268,21 @@ fn literal3(input: &mut &str) -> ModalResult<Date> {
 
 /// Parse the name of a month (case-insensitive)
 fn literal_month(input: &mut &str) -> ModalResult<u8> {
-    s(alpha1)
+    s((alpha1, opt('.')).take())
         .verify_map(|s: &str| {
             Some(match s {
-                "january" | "jan" => 1,
-                "february" | "feb" => 2,
-                "march" | "mar" => 3,
-                "april" | "apr" => 4,
-                "may" => 5,
-                "june" | "jun" => 6,
-                "july" | "jul" => 7,
-                "august" | "aug" => 8,
-                "september" | "sep" | "sept" => 9,
-                "october" | "oct" => 10,
-                "november" | "nov" => 11,
-                "december" | "dec" => 12,
+                "january" | "jan" | "jan." => 1,
+                "february" | "feb" | "feb." => 2,
+                "march" | "mar" | "mar." => 3,
+                "april" | "apr" | "apr." => 4,
+                "may" | "may." => 5,
+                "june" | "jun" | "jun." => 6,
+                "july" | "jul" | "jul." => 7,
+                "august" | "aug" | "aug." => 8,
+                "september" | "sep" | "sep." | "sept" => 9,
+                "october" | "oct" | "oct." => 10,
+                "november" | "nov" | "nov." => 11,
+                "december" | "dec" | "dec." => 12,
                 _ => return None,
             })
         })
@@ -480,6 +480,8 @@ mod tests {
             "14-nov2022",
             "14nov2022",
             "14nov      2022",
+            "14 nov. 2022",
+            "14-nov.-2022",
         ] {
             let old_s = s.to_owned();
             assert_eq!(parse(&mut s).unwrap(), reference, "Format string: {old_s}");
@@ -529,6 +531,8 @@ mod tests {
             "nov 14 2022",
             "nov14 2022",
             "nov14, 2022",
+            "nov. 14, 2022",
+            "nov.14 2022",
         ] {
             let old_s = s.to_owned();
             assert_eq!(parse(&mut s).unwrap(), reference, "Format string: {old_s}");
@@ -584,6 +588,7 @@ mod tests {
             "nov-14-2022",
             "nov---14---2022",
             "nov  -   14    -   2022",
+            "nov.-14-2022",
         ] {
             let old_s = s.to_owned();
             assert_eq!(parse(&mut s).unwrap(), reference, "Format string: {old_s}");
diff --git a/src/items/mod.rs b/src/items/mod.rs
index 58c549b..617073f 100644
--- a/src/items/mod.rs
+++ b/src/items/mod.rs
@@ -134,18 +134,18 @@ pub(crate) fn parse_at_local<S: AsRef<str> + Clone>(input: S) -> Result<ParsedDa
 /// month               = dec_uint ;
 /// day                 = dec_uint ;
 ///
-/// literal_month       = "january" | "jan"
-///                     | "february" | "feb"
-///                     | "march" | "mar"
-///                     | "april" | "apr"
-///                     | "may"
-///                     | "june" | "jun"
-///                     | "july" | "jul"
-///                     | "august" | "aug"
-///                     | "september" | "sept" | "sep"
-///                     | "october" | "oct"
-///                     | "november" | "nov"
-///                     | "december" | "dec" ;
+/// literal_month       = "january" | "jan" | "jan."
+///                     | "february" | "feb" | "feb."
+///                     | "march" | "mar" | "mar."
+///                     | "april" | "apr" | "apr."
+///                     | "may" | "may."
+///                     | "june" | "jun" | "jun."
+///                     | "july" | "jul" | "jul."
+///                     | "august" | "aug" | "aug."
+///                     | "september" | "sept" | "sep" | "sep."
+///                     | "october" | "oct" | "oct."
+///                     | "november" | "nov" | "nov."
+///                     | "december" | "dec" | "dec." ;
 ///
 /// time                = iso_time | meridiem_time ;
 ///
diff --git a/src/lib.rs b/src/lib.rs
index 96a3962..6b1e9f9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -345,6 +345,24 @@ mod tests {
             assert_eq!(parse_datetime("05/7/1987").unwrap(), expected);
             assert_eq!(parse_datetime("05/07/1987").unwrap(), expected);
         }
+
+        #[test]
+        fn month_abbreviation_with_period() {
+            let months = [
+                "jan.", "feb.", "mar.", "apr.", "may.", "jun.", "jul.", "aug.", "sep.", "oct.",
+                "nov.", "dec.",
+            ];
+            for (i, month) in months.iter().enumerate() {
+                let input = format!("{month} 5 2024");
+                let actual = parse_datetime(&input).unwrap().expect_in_range();
+                assert_eq!(actual.month() as usize, i + 1, "{input}");
+                assert_eq!(actual.day(), 5, "{input}");
+            }
+
+            for input in ["sept. 5 2024", "june. 5 2024", "jan.. 5 2024"] {
+                assert!(parse_datetime(input).is_err(), "{input}");
+            }
+        }
     }
 
     #[cfg(test)]