Avoiding M25 delays - advice wanted

[BGarside]

Off on holiday a week on Friday and I need to drive from Somerset to Gravesend to catch a bus. So, going to have to use the M25 between Chertsey and Dartford. I have to reach Gravesend before 9pm and Google Maps suggests a 3h drive.

Not sure what time to travel to avoid getting stuck on the M25, which I never venture onto normally. Should I travel early or late?

Ta for any advice.

[BGarside]

Thanks. Leaving it late looks like too much of a gamble. Guess I'll take the day off work and arrive early instead...

[BGarside]

Annoying to have to lose a day's pay just to make a 3 hour drive to get somewhere by 9pm!

[BGarside]

Thanks. Will probably travel early and get to Gravesend at lunchtime then have to kill some time in Gravesend...