Blogger Time Zone Issues

I noticed that the time on my last post was wrong (because my time zone was still set to pacific time). I changed my settings to fix it and all future posts, but it means all the old posts I made from California now are off by three hours. Apparently I cannot set it so it displays the time zone in the post-time-and-date field or mark particular posts as made in a different time zone. I suppose I could go an manually change all the times for all the west coast posts but that seems silly. I wonder how many people have run into this blogger issue before..