End Google Ads 201810 - BS.net 01 --> Hello

Can anyone tell me how to convert Julian date/time to Normal (standard) date/time
and back?

Any sample source code will help?

I do have some code, but the problem is, if the TIME is before 12 Noon, then it will
show the previous DAY.

i.e., if the actual time now is Sep 17th 10:30 AM

My code will give me the date as Sep 16th 10:30 AM

But if the current time is Sep 17th 10>30 PM

then it will give the exact day.