It varied between firms. For Osborne Clarke and Weil I was doing 9:30 – 6:00/6:30, whereas for Jones Day, it was more like 8:30/9:00 – 7:30/8:00. Simmons was somewhere in between.
That’s excluding the social events, which some firms emphasised more than others. The bigger social events would often run late – one was an overnight office party (we stayed in a hotel) – though I must say I preferred the shorter ones!