Traditionally it has been Tuesday - Thursday, between 10-11am and 8pm - 12 am user's time...however recently the heterogeneity between days and time is getting less and less; maybe because people no longer have 'traditional' weeks and there is less delination of work vs personal time - eg most people work 6-7 days a week rather than the traditional mon-fri, and people do non-work browsing (eg checking personal emails, watching yt videos) both during off time and during work time...
Mancar