I shop at a Weis in my area. I believe the miles expire quarterly. It shows on your receipt. It's the same for everyone, no matter when you earned the points. For example, in my area the next expiration date is Dec. 27.
FOLLOW-UP 11/17/14:
1. Visited three Weis stores. Some Weis stores have the variable $20-500 Visa GCs, some do not. $500 card = 100 pts, or $1 off/gal up to 20 gals.
(Their inventory is much less than Giant; it may be hard to find the $500 denom GCs needed to make this consistently worthwhile)
2. Some stores check ID to see that it matches the name on the credit card; some do not.
3. Store may fill out a form with DL info when $2000 or more in GC purchase at one time made. Not all stores follow this.
4. Manager override needed at 2 stores for over $300 purchase, but one store allowed $500 GC purchase with no mgr needed.
5. AMEX GC could be used at 2 of 3 stores, but last store disallows. Best to have custom AMEX GC with name imprinted if using them.
6. Points cycle seems to run quarterly, next expiration is late March 2015 for pts. earned approx. Jan 1 - late March.
Current expiration of pts is Dec 27.