Yes, often free spins do come with associated time limits. These limits can vary widely between different online casinos and specific promotions. Free spins often come with an expiration date. This means you must use the spins before a certain date, or they will be removed from your account. This could range from a few days to a couple of weeks or more, depending on the specific promotion.
Some online casinos may require any winnings from free spins to be wagered within a certain time frame. If you don't meet these wagering requirements within the set time limit (for example, 30 days), you may forfeit your winnings.
In some cases, a casino might offer daily free spins as part of a promotion. These spins usually need to be used within a 24-hour period.