Translations:Using regular expressions/112/zh-cn
From LimeSurvey Manual
/^(?:00:[0-5][0-9]:[0-5][0-9] (?:am|AM)|(?:0[1-9]|1[01]):[0-5][0-9]:[0-5][0-9] (?:[ap]m|[AP]M)|12:[0-5][0-9]:[0-5][0-9] (?:pm|PM))$/
/^(?:00:[0-5][0-9]:[0-5][0-9] (?:am|AM)|(?:0[1-9]|1[01]):[0-5][0-9]:[0-5][0-9] (?:[ap]m|[AP]M)|12:[0-5][0-9]:[0-5][0-9] (?:pm|PM))$/