Timestamp ? to date/time

Hi All,

Not quite sure on how to ask this.
I have a payload (updatetime) which contains something like a timestamp. (pic2)
The strange thing is however that I thought it was EPOCH time, but is seems shorter.
However, when I click on that number in the debug window, it changes to a date/time. (pic1)
That date/time is what I need as output of the flow, but how to convert this ?
If I convert it like if it was epoch , then I get a completely wrong date/time (in 1970)
Someone can help me out here ?
afterclick pic1

The number is probably in seconds. Your conversion may be expecting mS so maybe multiply by 1000

That looks like a valid javascript time.
How are you converting it so that you get 1970?