Javascript lastModified appears to be returning wrong date

I have some basic javascript code in a footer on a standard web page (ie. not WordPress or anything like that). I modified the page yesterday evening (11/20 at about 7 p.m. EST), but the date showing up on the page is today (11/21) at 00:36:26. I’m less concerned about the page being off by a few hours than I am by not knowing why it’s off. I’m concerned that tomorrow, a different date might appear. Does anyone know anything about why lastModified might be wrong?

Site is at . And I know it’s ugly. It’s a practice area I’m using to teach students various technical tools and techniques :-).

The date you’re looking at is the last-modified date of the page in GMT. If you want it in your local time zone, you’ll need to convert it.