Translations:Using regular expressions/111/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))$/
/^(?:00:[0-5][0-9](?::[0-5][0-9])? (?:am|AM)|(?:0[1-9]|1[01]):[0-5][0-9](?::[0-5][0-9])? (?:[ap]m|[AP]M)|12:[0-5][0-9](?::[0-5][0-9])? (?:pm|PM))$/