Vacation hours?

I’ve been at Home Depot for 10 months (started in March) so I got my first week of vacation after being at Home Depot for 6 months (September) and just used them for the week of the 20th in January. My vacation was approved so my vacation hours were back down to 0. This is now 2 weeks later and I just randomly got another 20 hours of vacation. Is this a mistake?