how to convert seconds to time format?

[airysoar]

hi there for some reason i convert a time format like : 03:30 to seconds 3*3600 + 30*60 , now .. i wanna convert it back to it's first ( same ) format upthere ... how could that be ?My attempt : 3*3600 + 30*60 = 12600 12600 / 60 = 210 / 60 = 3.5 , floor(3.5) = 3 = hournow .. what about the minutes ?? considering the value can be like 19:00 or 02:51 ... i think you got the picture and by the way, how to convert 2:0 for example to 02:00 using RegEx ?Thanks in advance