XF 1.5 How to check user upgrade time left and display in a template.

I'm trying to make a sidebar widget (using widget framework) that displays how much longer a user has for their upgrade on my forum. I already made the conditional statement depending on if they are in a certain user group, however I cant find the variables in relation to user upgrades. I'm simply looking to know when a user first got their upgrade, and the date/time of which the upgrade ends. If anyone can help, that would be greatly appreciated!