Saving current date and time

Posted by KaiserBear on Sat 03 Oct 2015 09:17 AM — 3 posts, 13,949 views.

KaiserBear Sat 03 Oct 2015 09:17 AM #0

I'm trying to make a trigger that would save all aspects of the current date and time, but I don't know how. I looked at time.os but it doesn't really make sense to me. Can someone show/tell me how to do this step by step? I'd be looking to fill the following variables:

currentDay
currentMonth
currentYear

currentHour
currentMinute
currentSeconds
amOrPm (or, adding +12 to currentHour when the time is pm - to convert to military time)

All of these would be numbers, not the word date, ideally. So January 2nd, 2001 would have the currentMonth = 1, and currentDay = 2, etc. If I had to have the day/month that's fine, I could probably figure a workaround to convert that into a number. My problem is how to pull the data into the above variables, and I don't even know where to start right now.

Fiendish USA Global Moderator Sat 03 Oct 2015 10:09 AM #1

To help you out, I'll quote selectively from http://www.lua.org/pil/22.1.html

Quote:

22.1 – Date and Time

Two functions, time and date, do all date and time queries in Lua.

The time function, when called without arguments, returns the current date and time, coded as a number. (In most systems, that number is the number of seconds since some epoch.)

...

The date function, despite its name, is a kind of a reverse of the time function: It converts a number representing the date and time back to some higher-level representation. Its first parameter is a format string, describing the representation we want. The second is the numeric date-time; it defaults to the current date and time.

To produce a date table, we use the format string "*t". For instance, the following code

date_table = os.date("*t", 906000490)

produces the table

{year = 1998, month = 9, day = 16, yday = 259, wday = 4,
hour = 23, min = 48, sec = 10, isdst = false}

...

date tables have the following significant fields:
year a full year
month 01-12
day 01-31
hour 01-31
min 00-59
sec 00-59
isdst a boolean, true if daylight saving

...

Notice that, besides the fields used by os.time, the table created by os.date also gives the week day (wday, 1 is Sunday) and the year day (yday, 1 is January 1).

So you either want to do...


current_time = os.time()
date_table = os.date("*t", current_time)

or more simply, just


date_table = os.date("*t")

which is a shortcut for the former, but the former allows you to save a timestamp for later.

Then, for example, your "currentMonth" would be

currentMonth = date_table.month

You can verify for yourself the output of os.date with the following simple printing code...

for k,v in pairs(os.date("*t")) do
  print(k.." , "..tostring(v)) 
end

KaiserBear Sat 03 Oct 2015 10:32 AM #2

That works perfectly, thanks. I haven't messed with tables before with Lua, this helped a lot. I really appreciate the help.