+def unified_timestamp(date_str, day_first=True):
+ if date_str is None:
+ return None
+
+ date_str = date_str.replace(',', ' ')
+
+ pm_delta = datetime.timedelta(hours=12 if re.search(r'(?i)PM', date_str) else 0)
+ timezone, date_str = extract_timezone(date_str)
+
+ # Remove AM/PM + timezone
+ date_str = re.sub(r'(?i)\s*(?:AM|PM)(?:\s+[A-Z]+)?', '', date_str)
+
+ for expression in date_formats(day_first):
+ try:
+ dt = datetime.datetime.strptime(date_str, expression) - timezone + pm_delta
+ return calendar.timegm(dt.timetuple())
+ except ValueError:
+ pass
+ timetuple = email.utils.parsedate_tz(date_str)
+ if timetuple:
+ return calendar.timegm(timetuple.timetuple())
+
+