Add time to parsed date after parsing not before

Change the way dates without times are parsed by just parsing the date
as-is and applying the placeholder time (00:00:00) after parsing
instead of before.

Author: jfinkels

src/lib.rs

@@ -21,8 +21,8 @@ mod parse_time_only_str;
 mod parse_weekday;
 
 use chrono::{
-    DateTime, Datelike, Duration, FixedOffset, Local, LocalResult, MappedLocalTime, NaiveDateTime,
-    TimeZone, Timelike,
+    DateTime, Datelike, Duration, FixedOffset, Local, LocalResult, MappedLocalTime, NaiveDate,
+    NaiveDateTime, TimeZone, Timelike,
 };
 
 use parse_relative_time::parse_relative_time_at_date;
@@ -297,13 +297,12 @@ pub fn parse_datetime_at_date<S: AsRef<str> + Clone>(
         }
     }
 
-    let ts = s.as_ref().to_owned() + " 0000";
     // Parse date only formats - assume midnight local timezone
     for (fmt, n) in format::PATTERNS_DATE_NO_TZ {
-        if ts.len() >= n + 5 {
-            let f = fmt.to_owned() + " %H%M";
-            if let Ok(parsed) = NaiveDateTime::parse_from_str(&ts[0..n + 5], &f) {
-                if let Ok(dt) = naive_dt_to_fixed_offset(date, parsed) {
+        if s.as_ref().len() >= n {
+            if let Ok(parsed) = NaiveDate::parse_from_str(&s.as_ref()[0..n], fmt) {
+                let datetime = parsed.and_hms_opt(0, 0, 0).unwrap();
+                if let Ok(dt) = naive_dt_to_fixed_offset(date, datetime) {
                     return Ok(dt);
                 }
             }