Date/ Time conversation when all in same cell

i am trying to do a simple vlookup and am having problems bc one report is in GMT time zone and one report is in PST. here are the two cells that i want to match but need to convert one of them.

11/19/2014 22:14:06 GMT
2014-11-19 14:14:06

I have tried a TIME formula but unsucessful bc of the date in the cell. i know i can seperate the cell with text to column, but wanted to check with the experts on the forum to avoid the manual spilting and rejoing of the cells. thanks for taking time to look!! any suggesting appreciated!

=TEXT(DATE(YEAR(LEFT(G7,10)),MONTH(LEFT(G7,10)),DAY(LEFT(G7,10))),"yyyy-mm-d")&" "&TEXT(TIME(HOUR(MID(G7,12,8))-8,MINUTE(MID(G7,12,8)),SECOND(MID(G7,12,8))),"hh:mm:ss")
actually got this from another member and it worked perfectly!! the only issue now it i have some cells where the GMT time is making it the next day, when the PST date is the correct date..... so i changed the date by using a -1 on the day but the hour is 01:30:07, so if i -8, i get a NUM! error bc itwont convert the tme to -08:30:07, which i dont want that either, i want it to say 17:30:07. please let me know your thoughts!!