validate traditional time formats regex

validate traditional time formats

Hours and minutes, 12-hour clock:
┌──────────────────────────────────────────────┐
│ ^(1[0-2]|0?[1-9]):([0-5]?[0-9])(●?[AP]M)?$   │
└──────────────────────────────────────────────┘
Hours and minutes, 24-hour clock:
┌──────────────────────────────────────────────┐
│     ^(2[0-3]|[01]?[0-9]):([0-5]?[0-9])$      │
└──────────────────────────────────────────────┘
Hours, minutes, and seconds, 12-hour clock:
┌──────────────────────────────────────────────────────────────┐
│ ^(1[0-2]|0?[1-9]):([0-5]?[0-9]):([0-5]?[0-9])(●?[AP]M)?$     │
└──────────────────────────────────────────────────────────────┘
Hours, minutes, and seconds, 24-hour clock:
┌──────────────────────────────────────────────────────────────┐
│ ^(2[0-3]|[01]?[0-9]):([0-5]?[0-9]):([0-5]?[0-9])$            │
└──────────────────────────────────────────────────────────────┘
variation
----------
► Merely removing the anchors from the regular expression is not the 
  right solution.   That would allow the hour and minute regexes to 
  match 12:12 within 9912:1299, for instance. Instead of anchoring 
  the regex match to the start and end of the subject, 
example:
┌──────────────────────────────────────────────┐
│     \b(2[0-3]|[01]?[0-9]):([0-5]?[0-9])\b    │
└──────────────────────────────────────────────┘