What unit of measurement does "expires" use in tv.cache?
Hi all, I'm interested in analysing the iPlayer database so I'm working with the tv.cache file (going to bring it into Tableau to do some visualisations). I've read the file into R, and exported it as a .csv file (using "|" as the delimeter). However, some of the columns have me baffled - most make sense, e.g. "name" refers to title of series/film, "episode" refers to the episode, etc. Some weren't clear to begin with, but I figured out, e.g. "duration" uses seconds as the unit, so all you have to do is divide by 60 to get the duration in minutes. However, one column that doesn't make sense to me is "expires". Here's an example of the data: 1561382400.

Does anyone know what unit this is using? The title in question supposedly expires in 11 days (according to its page on the iPlayer). It would also be helpful if someone could point me in the direction of any further information about the data stored in the cache, assuming it exists?
It's a Linux system timestamp

Where 1561382400 would be Monday, 24 June 2019 13:20:00 UTC

Info https://en.wikipedia.org/wiki/Unix_time
Calculator https://www.epochconverter.com/
Brilliant, that all makes sense now. Had never heard of this before!

Thanks for the quick reply.
Technically it's the Unix time (or Unix epoch). It's the number of seconds since 00:00:00 January 1st 1970 (UTC to be exact, and minus leap seconds). Pretty common in time measurements in computer applications.