To ask for urgent help fixing my self-inflicted cockup here due to high traffic?

[ElectricMonk]

Basically, I have a 1 hour seminar on Monday and may be doing an assessed presentation in that subject the following week. I have been assigned a supervisor to advise on the presentation, and booked an appointment to see her which I have accidentally scheduled for halfway through the seminar. It was impressively daft of me, I know - if it's any defense, I was extremely tired when I booked the appointment and wrote my seminar start time rather than my seminar finish time when giving a list of "times I'm not free".

Other relevant information: seminar is compulsory, it's an important one because we'll be agreeing presentation times, it's on the same corridor as supervisor's office, and supervisor is very nice but rather intimidating and I don't know her very well. Won't be able to speak to supervisor or seminar leader beforehand, but can send e-mails and hope they read them in time.

Suggestions would be much appreciated!

Umm, I might be missing something but cant you just email supervisor, say you made an error with the times and ask her to reschedule?

Yep, e-mail supervisor and apologize for the mistake. Don't make excuses, just apologize and ask if there is a time you can re-schedule for.
Any chance you could get there early enough to apologise to supervisor before seminar? facing up in person always better option.

Thank you both for the advice! I'd like to apologise in person but I doubt I'll manage to see her beforehand, I usually only just make it to that seminar in time as I have something else first.

I'll e-mail her, since you both think it's okay - I know I'm prone to worrying too much about things like this! I just find it very hard because being reliable and organised has always been very important to me, but I'm so stressed and overtired this year that even though I double-check everything carefully I end up making really odd mistakes like this every now and then... :(

Just email her and ask to reschedule. These things happen, and it really isn't a big deal. If she is a busy person then you asking to move it to a later date will probably be welcome.