Ping times?

Hi,

Currently on Nildram, but talktalk phoned up today and offered us broadband and telephone for cheaper than I currently pay for just the internet! I've been reading that the monthly limit is 40gb which sounds alright, but is there a time of day where it doesnt count towards the usage? (like 12-8am or something), and does any unused allowance carry over to the next month?

Also, I play online games quite a bit and was wondering what the pings are like?

Cheers.