Blind Date and Times

Question

_{This puzzle is part of the Monthly Topic Challenge #6: Is it really that [time] again?.}

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I was going on a blind date with a fellow puzzler and they sent me this:

I didn't end up going on the date, got mixed messages. But if I did, how might I have recognized them?

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Transcript:

A: Ok, so the pier it is then! When should we meet?

B: I can do exclusively 1:17 or 7:56 or 6:21

B: Hopefully that doesn't raise any red flags

A: That works, and how will I recognize you?

B: I'll wear a distinctive three letter accessory.
   If you're my age and as good a puzzler as you say,
   you should be able to figure it out :)

A: I knew I shouldn't have expected a straight answer 🙄

Answer 1

Your partner will wear a

WIG.

Looking at the times they gave you,

we can make three clock faces. Then as hinted by red flags, we decode them as flag semaphore.

which gives the three letter word 'wig'.

However, I am not sure how you can recognize that, unless I am missing something in the message. But since you're their age and good a puzzler, you will be able to figure it out.