Is this something to be worried about or will it blow over.

Don't stress, if he says 5:00pm doesn't work, try to schedule something afterwards. This isn't a mistake, you're fine.

CompBanker thank you for the quick response, however maybe I should've added that my MD was cc in the e-mail so he got it also. Should I even bring it up with him. (sorry if this issue is mundane, it's just very critical I must do my best at this internship)

Nope, don't point out your mistake. If he mentions it, acknowledge that you erred but I doubt that will happen.

Comp Thanks for your worldly insight. My MD just walked back in office and we had a conversation about the potential client while the e-mail was open with no mention of the mistake! I know again probably extremely insignificant but I am tremendously relieved and will now delete the original post so there is no potential embarassment/connection!. Thank you again COMP!