How to round unix timestamp up and down to nearest half hour?

Question

Ok so I am working on a calendar application within my CRM system and I need to find the upper and lower bounds of the half an hour surrorunding the timestamp at which someb

Answer 1

I'd use the localtime and the mktime function.

$localtime = localtime($time, true);
$localtime['tm_sec'] = 0;
$localtime['tm_min'] = 30;
$time = mktime($localtime);