First day at work question

Hi guys, just wanted a few opinions or someone to tell me if I’m being dense (probably am haha).

So I got an offer letter to start a new lab job, and mentioned to come into the lab at 10am and meet XY (my interviewer). Now, the start date was provisional so had a chat with the recruitment manager and she changed it to a suitable date a few weeks back. This amended offer letter had basically everything the original one had except no mention of what time I should come into the lab.

The original job description says working times are 8.30-5pm Mon-Fri. Am I being mistaken that I should still be coming in at 10am that first day, as stated in the original offer letter? 😅

Thanks, just my nerves for a new job making me question these basic things…