The selection is in local time, and the result is UTC – seems to work fine.
May 6 2AM – May 7 5AM returns
May6 8AM UTC → May 7 11AM UTC … and correct with -6 hours for my timezone
Here is the code to convert the month day forward or back a few hours - as you see the date changes at 6AM UTC for my timezone of -6. Paste this into a cell and format as Date, and change -6 as required.
=DATE(MID(A2,12,4),MONTH(1&MID(A2,5,3)),MID(A2,9,2))+(-6*3600+MID(A2,17,2)*3600+MID(A2,20,2)*60+MID(A2,23,2))/(24 * 3600)
