Nightfall happens in almost less than a minute, is this normal?

I just started playing it yesterday and it does change pretty quick, it seems like its less than 2 minutes for me. I basically run, get in a fight and then have to camp because its night time. It is kind of ridiculous.

I played this game in 1998 and I don't remember this being an issue.

I haven't played Betrayal in Antara yet, but in Betrayal at Krondor, time only moves when my party moves. So if I hold down the "march forward" button, then time advances rapidly and nightfall could come quickly. Perhaps this behavior is the same in Betrayal in Antara?

It's the same. There is a speed issue which, AFAIK, causes nightfall to occur too quickly, but I think the GOG version already has that fix? Might help to set Step Size to small. See if I can't remember to check starting a new game with the fixed CD version.