Sorry for the ask on this one.....

how long is a gift code good for? Can I purchase it now, have it sent to my email, and then give it to someone for Christmas or Valentine's day (February 14)?

Gift codes that are purchased by the user never expire.

Absolutely! As long as you BUY the code here, it will never expire. Some codes that GoG gives away DO expire, and if you buy the code from one of the bundle sites (Humble, etc) it MAY expire.

But if you buy it here on GoG that sucker will last until it's used.

ProTip: If you save it until Valentine's Day, make sure you get her flowers, too.

That's good news! Thank you! And thanks for the fast repsonse!