os.time() unable to read in UTC times

[Asko Kauppi <askok@...>]

I've got historical UTC timestamps, and I want to get the  
corresponding local time (based on the OS's locale) for them.

This cannot be done in Lua 5.1 since 'os.time()' only calls for  
'mktime()', never 'timegm'.  These two are a pair, and described  
together on the man pages (man mktime). mktime is for creating epoch  
ticks out of local time; timegm is for doing the same from UTC time.

Is there a reason for the omission, and could 'os.time()' support UTC  
input in the future?

For example, add a second parameter (boolean), or '.utc=true' to the  
current calling scheme. Both would be backwards compatible.

-asko

Oh, well...
"The timegm function is not specified by any standard; its function  
cannot be completely emulated using the standard functions described  
above."
http://www.gsp.com/cgi-bin/man.cgi?section=3&topic=timegm

It's annoying to see the ANSI limitations limiting Lua time and again.