I have some video files captured automatically and given file names
which must be date/times. Here are a couple of examples:

1550820358.MOV was captured at about 07:25 on 22nd Feb 2019.
1550823001.MOV was captured at about 08:10 on the same morning (today).

So they must be in seconds from some base date. To avoid reinventing
this particular wheel, could someone kindly share a formula and/or VBA
macro that would convert those numbers to a date and time in my
favourite format please.

IOW, convert 1550820358 to 20190222-072558, i.e. just before 7:26 am on
22nd February 2019.

Terry, East Grinstead, UK