A- take the Gamin off and let your wrist heal...at least while you are on the track. You may want to rinse the band off as constant sweating may cause a salt build up that increases irritation. Zeke gave great ideas/links to calculate the distance on the track. I would think that even a Garmin isn't so accurate that it would be useful on the track(for distance). What it really comes down to is what & why you are timing. For me a simple multi-lap watch does fine. I run warm, cool down and recouperation laps in the outside lane, only speed on the inner lane. It's about four laps to a mile and I don't worry about the extra bits, and I jog to and from the parking lot. But then I don't do long runs on the track either.
the other issue: pedicure. I had one once as my husband gave me a gift card one Christmas. It was fun to say I've done it but I can think of dozens of better ways to use my money.