Trial version counting down quickly

I download the trial version and expected to get 30 days to test the product, but it seems that I’m losing some days. For example, I opened the software this morning (March 23), and it said I had 15 days left. I closed it a little while later, then opened it again this evening (still March 23) and it said I had 14 days left. The same thing happened to me a few times earlier, too. Does anyone know what’s going on?