address review comment

https://github.com/rust-lang/rustc-dev-guide/pull/1394#discussion_r934018268

This led to a more robust regex, though making the tool more picky.
It also found a wrong date format that was missed.

ci/date-check/src/main.rs

@@ -38,8 +38,8 @@ impl fmt::Display for Date {
 
 fn make_date_regex() -> Vec<Regex> {
     let patterns = [
-        r"<!--\s+date-check:\s+(\w+)\s+(\d+{4})\s+-->",
-        r"<!--\s+date-check\s+-->\s+(\w+)\s+(\d+{4})",
+        r"<!--\s+date-check:\s+(\D+)\s+(\d{4})\s+-->",
+        r"<!--\s+date-check\s+-->\s+(\D+)\s+(\d{4})\b",
     ];
     let set = RegexSet::new(&patterns).unwrap();
     set.patterns()
@@ -198,6 +198,20 @@ mod tests {
         assert!(regexes[1].is_match("<!-- date-check --> january 2021"));
         assert!(regexes[1].is_match("<!-- date-check --> Jan 2021"));
         assert!(regexes[1].is_match("<!-- date-check --> January 2021"));
+
+        assert!(regexes[1].is_match("<!-- date-check --> jan 2021 "));
+        assert!(regexes[1].is_match("<!-- date-check --> jan 2021."));
+    }
+
+    #[test]
+    fn test_date_regex_fail() {
+        let regexes = &make_date_regex();
+        assert!(!regexes[0].is_match("<!-- date-check: jan 221 -->"));
+        assert!(!regexes[0].is_match("<!-- date-check: jan 20221 -->"));
+        assert!(!regexes[0].is_match("<!-- date-check: 01 2021 -->"));
+        assert!(!regexes[1].is_match("<!-- date-check --> jan 221"));
+        assert!(!regexes[1].is_match("<!-- date-check --> jan 20222"));
+        assert!(!regexes[1].is_match("<!-- date-check --> 01 2021"));
     }
 
     #[test]

src/building/suggested.md

@@ -22,7 +22,7 @@ You can also install the hook as a step of running `./x.py setup`!
 a file. By default, `rust-analyzer` runs the `cargo check` and `rustfmt`
 commands, but you can override these commands to use more adapted versions
 of these tools when hacking on `rustc`. For example, for Visual Studio Code,
-you can write: <!-- date: 2022-04 --><!-- the date comment is for the edition below -->
+you can write: <!-- date-check: apr 2022 --><!-- the date comment is for the edition below -->
 
 ```JSON
 {

src/contributing.md

@@ -447,9 +447,10 @@ Just a few things to keep in mind:
     There is a CI action (in "~/.github/workflows/date-check.yml")
     that generates a monthly issue with any of these that are over 6 months old.
 
-    For the action to pick the date, add this annotation:
+    For the action to pick the date,
+    add a special annotation before specifying the date:
 
-        <!-- date-check -->
+        <!-- date-check --> Jul 2022
 
     Example: