Another similar idea was proposed, please take a look: https://www.djsoft.net/smf/index.php/topic,4651.msg22285.html#msg22285
It merely allows specifying multiple start times - that, theoretically, can cover any possible "start time" needs (each "start time" in the list will have all the features of the "start time" the event already has: time, date, days, weeks etc).
What do you think about it?