When you're on a diligent job search, the last thing you want to do is turn down an interview because you already have something else on your schedule that you cannot possibly cancel. You also don't want to lose the opportunity to interview just because you can't make it at the time the recruiter proposed. A pleasant and polite request to reschedule the interview should be fine, provided you don't wait until the last minute to inform the recruiter or hiring manager of your scheduling conflict.
Initiate your email contact with the recruiter or hiring manager who proposed the interview as quickly as you can to discuss rescheduling. You may need to follow up with a telephone call after writing the email, but always have written correspondence about the interview day and time.
Express your appreciation for being scheduled for an interview in the first sentence of your email message. Lock in your interview by saying that you're looking forward to being considered for the job. Follow up with a brief sentence that you have a conflict in your schedule, and that you want to reschedule for a time that's mutually convenient.
Provide several options from which the recruiter can select an alternate day and time. Check your calendar to note the days and times when you're available for rescheduling the interview. Group those alternatives in logical order to insert in your email. For example, instead of writing, "I'm available every afternoon, except Wednesday, from noon until 4 p.m.," write "I'm available Monday, February 25, and Tuesday, February 26, from noon until 4 p.m. each day. I'm also available Thursday, February 28, and Friday, March 1, from noon until 4 p.m. each day." Ask the recruiter to confirm the preferred time with you via email or a phone call, and include your phone number.
Close your email by reiterating your interest in the company and the job, and say that you're looking forward to meeting the recruiter you're writing to. Use a respectful closing salutation for your email, such as "Kind regards," or simply, "Regards."
