Date formatting in Lua

Question

I am retrieving a date from a database in the following format:

vardate =  '01/20/2017 09:20:35' - mm/dd/yyyy hh:mm:ss

I want to convert it to the format dd-mm-yyyy hh:mm:ss

Can I get some guidance on how I could get the format I want?

Answer 1

Date formatting in Lua is pretty simplistic. If you only need to convert it from one format to another, and that format does not change, you could simply use string.match:

function convertDate(vardate)
    local d,m,y,h,i,s = string.match(vardate, '(%d+)/(%d+)/(%d+) (%d+):(%d+):(%d+)')
    return string.format('%s/%s/%s %s:%s:%s', y,m,d,h,i,s)
end

-- Call it this way
convertDate('01/20/2017 09:20:35')

If you need something more involved, I suggest using an external library.

Answer 2

function ConvertDate(date)
  return (date:gsub('(%d+)/(%d+)/(%d+) (%d+:%d+:%d+)','%2-%1-%3 %4'))
end

-- test
print(ConvertDate('01/20/2017 09:20:35'))