Thanks, all! I guess mine's got a little time on it yet!

The brand I buy doesn't require refrigeration. For me, keeping it out amongst my various bottles of oils and vinegars and sauces encourages me to use it faster. It makes an amazing sauce over some steamed carrots, or a fabulous dip that I use as a healthy alternative to mayo - just add 2 tablespoons to a cup of nonfat yogurt with a healthy squeeze of lemon and a pinch of salt.

months? years!

I don't think tahini needs refrigeration -- haven't for the last 40+ years. And no, I don't have any 40 year old tahini. I do use it up.

Since I only use tahini in my hummus, I have had some stay in the fridge for months and it never went bad. I have found if tahini develops lumps you can easily get rid of them if you blend it for a few seconds with a teaspoon of water. Alternatively, whisking hard in a bowl with a teaspoon of water can eliminate the lumps, both ways may require more tahini as it will be slightly less flavorful.

I have had some for several months that is fine!!

It never seems to go bad, but unless you give it a good stir every week or so, the solids get really hard to re-incorporate after a few months.