After reading other posts in the forum from people who were experiencing this problem, one fix people were mentioning is that, if your date settings say "BE" after it (as you mentioned), then your calendar somehow got set to the Buddhist calendar. To change it back to the 'proper' (Gregorian) calendar, go to Settings > General > International > Calendar , then change it back to Gregorian. Some people said this fixed their issue.
I was also experiencing this problem, however that particular fix did not work for me. I had not used my ipod touch in a while so the battery was completely dead. After plugging it in while I fiddled with it, I first tried resetting default settings (NOT a full wipe) with no success. I then read someone mentioning trying to sync it with iTunes while it's plugged into your computer, and that did not seem to work at first because the date & time were still wrong. However, a couple minutes after I had synced it with iTunes, it finally LET me manually change the date & time, whereas before it would not let me.
I had read on yet another post that someone said they left their ipod charging for a while before they tried messing with it, and it was back to normal by the time they came back to it once it charged. Therefore, I'm not sure if the date & time got screwy simply because it had died a while back and had not been turned on since, therefore just needing to charge for a few minutes... or if the sync method is actually what did the trick. In any event, definitely try reading multiple posts that suggest different fixes to try BEFORE you go performing a full wipe or doing anything drastic. That was the first suggestion I saw, and I figured there HAD to be an easier way. Luckily, I was right!