Calculate time in Excel

i have two columns in xl sheet A row have this format "8:25 PM EDT" and B row have this format "10:12:15 AM" , Now i want to add one hour to the B column if the A c开发者_Go百科olumn contains the text "EDT" , Please help me to find out the solution Thanks in advance.

edited: IFERROR(IF(FIND("EDT",A1)>0,B1+TIME(1,0,0)),A1)