Using os.date to output arbitrary date/time formats

The os.date function is great for outputting arbitrary date/time formats. It’s straightforward to use, here is an example in this case formatting the current time:

Here is another example, in this case we parse the input time using the fuzzy date parser and then output it using os.date:

You can see how flexible os.date is – especially if you mix it in with using the Lua string library for doing arbitrary string handling.

The formatting codes accepted within the date formatting string are the same as those supported by strftime. This table shows the available codes:

One useful trick for getting the date/time in a useful format is to use this:

local T = os.date("*t")

This returns a Lua table of date/time components, i.e.:

For more documentation on os.date and os.time see the Lua reference manual online.

The following code snippet is handy in exercising all the different available formatting codes:

function CurrentTime()
   local F = [[%%a=%a
%%A=%A 
%%b=%b 
%%B=%B 
%%c=%c 
%%d=%d 
%%H=%H 
%%I=%I 
%%j=%j 
%%m=%m 
%%M=%M 
%%p=%p 
%%S=%S 
%%U=%U 
%%w=%w
%%W=%W
%%x=%x
%%X=%X
%%y=%y   
%%Y=%Y    
]]
   return os.date(F, os.time())
end