These days, it basically depends on the client - quite a bit of work is remote if the client does not want a team on site. But in the old days, you were flying out on Monday morningat ridiculous times to be with the client when they start their week and then return on a Thursday, usually with the last flight back.
As a junior on a project pre-Covid, you usually spent four days with the client (Monday-Thursday) and Friday in your office. Depending on where the client is located, that means a very early start on Monday, cathcing the first available train/flight, filled to the brim with other tired consultants. You usually finished work a tad earlier on Mondays to balance that, Tuesdays and Wednesdays post-midnight and Thursdays travelling back with the last flight/train, so leaving in the late afternoon (plus a couple of drinks in the lounge ) and arriving back home at a somewhat decent time.