I've messing with some DATS recently (as if that was of any surprise) and when I consulted the specs for some value, I noticed that none of the 'Time'-related properties stored in different DATs (I run a wide search for it) had their time units defined.
So, I sat down, thought for a moment, run SC a few times, and here are my findings:
#1-Unit's build Time, Tech research Time and both normal and 'factor' Upgrade Time properties are using
1/15th of a second as 1. That is, if you input, say, '150' , the research will take 150/15 = 10 seconds.
This can be easily guessed if you recalculate the Hex values against what StarEdit allows you.
#2-Weapons Cooldown time. Now, this was a real challenge. At the beginning I thought that this too may use the same unit as the others - 1/15 of a sec. This was not the case however (what I realised when I modded SC and checked that Cooldown of 150 does not make the unit attack each 10 secs).
Then came a boring and tiring process of checking each other possibilitiy: 16, 17, 18, 19 etc.
I'll shorten your pains and tell you right away - the cooldown is scaled using....
1/23rd of a second! (which means that if you want the weapon to be used every 1 second, you need to input '23' as its cooldown).
Don't ask me why this is like that - Blizzard do have their own mysterious designs....