Add hour/minute/seconds formatting to date format strings.

src/calibre/manual/template_lang.rst

@@ -258,6 +258,14 @@ The following functions are available in addition to those described in single-f
         MMMM : the long localized month name (e.g. "January" to "December"). 
         yy   : the year as two digit number (00 to 99). 
         yyyy : the year as four digit number.
+        h    : the hours without a leading 0 (0 to 11 or 0 to 23, depending on am/pm)
+        hh   : the minutes with a leading 0 (00 to 11 or 00 to 23, depending on am/pm)
+        m    : the minutes without a leading 0 (0 to 59)
+        mm   : the minutes with a leading 0 (00 to 59)
+        s    : the seconds without a leading 0 (0 to 59)
+        ss   : the seconds with a leading 0 (00 to 59)
+        ap   : use a 12-hour clock instead of a 24-hour clock, with 'ap' replaced by the localized string for am or pm.
+        AP   : use a 12-hour clock instead of a 24-hour clock, with 'AP' replaced by the localized string for AM or PM.
         iso  : the date with time and timezone. Must be the only format present.
     
     * ``eval(string)`` -- evaluates the string as a program, passing the local variables (those ``assign`` ed to). This permits using the template processor to construct complex results from local variables.

src/calibre/utils/date.py

@@ -170,11 +170,37 @@ def format_date(dt, format, assume_utc=False, as_utc=False):
     if format == 'iso':
         return isoformat(dt, assume_utc=assume_utc, as_utc=as_utc)
 
+    ampm = 'ap' in format.lower()
+
     if dt == UNDEFINED_DATE:
         return ''
 
     strf = partial(strftime, t=dt.timetuple())
 
+    def format_hour(hr):
+        l = len(hr)
+        h = dt.hour
+        if ampm:
+            h = h%12
+        if l == 1: return '%d'%h
+        return '%02d'%h
+
+    def format_minute(min):
+        l = len(min)
+        if l == 1: return '%d'%dt.minute
+        return '%02d'%dt.minute
+
+    def format_second(min):
+        l = len(min)
+        if l == 1: return '%d'%dt.second
+        return '%02d'%dt.second
+
+    def format_ampm(ap):
+        res = strf('%p')
+        if ap == 'AP':
+            return res
+        return res.lower()
+
     def format_day(dy):
         l = len(dy)
         if l == 1: return '%d'%dt.day
@@ -193,17 +219,23 @@ def format_date(dt, format, assume_utc=False, as_utc=False):
         if len(yr) == 2: return '%02d'%(dt.year % 100)
         return '%04d'%dt.year
 
+    function_index = {
+            'd': format_day,
+            'M': format_month,
+            'y': format_year,
+            'h': format_hour,
+            'm': format_minute,
+            's': format_second,
+            'a': format_ampm,
+            'A': format_ampm,
+        }
     def repl_func(mo):
         s = mo.group(0)
         if s is None:
             return ''
-        if s[0] == 'd':
+        return function_index[s[0]](s)
-            return format_day(s)
-        if s[0] == 'M':
-            return format_month(s)
-        return format_year(s)
 
-    return re.sub('(d{1,4}|M{1,4}|(?:yyyy|yy))', repl_func, format)
+    return re.sub('(s{1,2})|(m{1,2})|(h{1,2})|(ap)|(AP)|(d{1,4}|M{1,4}|(?:yyyy|yy))', repl_func, format)
 
 def replace_months(datestr, clang):
     # Replace months by english equivalent for parse_date

src/calibre/utils/formatter_functions.py

@@ -747,6 +747,14 @@ class BuiltinFormatDate(BuiltinFormatterFunction):
             'MMMM : the long localized month name (e.g. "January" to "December"). '
             'yy   : the year as two digit number (00 to 99). '
             'yyyy : the year as four digit number. '
+            'h    : the hours without a leading 0 (0 to 11 or 0 to 23, depending on am/pm) '
+            'hh   : the minutes with a leading 0 (00 to 11 or 00 to 23, depending on am/pm) '
+            'm    : the minutes without a leading 0 (0 to 59) '
+            'mm   : the minutes with a leading 0 (00 to 59) '
+            's    : the seconds without a leading 0 (0 to 59) '
+            'ss   : the seconds with a leading 0 (00 to 59) '
+            'ap   : use a 12-hour clock instead of a 24-hour clock, with "ap" replaced by the localized string for am or pm '
+            'AP   : use a 12-hour clock instead of a 24-hour clock, with "AP" replaced by the localized string for AM or PM '
             'iso  : the date with time and timezone. Must be the only format present')
 
     def evaluate(self, formatter, kwargs, mi, locals, val, format_string):