Yesterday, it was down for some minutes as well, and prior to that for hours.
I have never faced such problem, so it might be due to network problem and sometimes development works. Especially since I just watched all the episodes of Pahela April Fool. The forum is working on a special type of development so it is normal to have forum downtime for some time.
I confirm on downforeveryoneorjustme if it's me or everyone. If you didn't face it you were probably inactive during that time.
What's Pahela April Fool?