Reading and comparing dates in Arduino Mega 2560

Hello guys, as you can see, I'm a freshman in this forum and, as you can't see, so in Arduino world. I'm working on a project that I have to make my Arduino read a .txt doc full of dates and hours of reunions in SD card and make the comparison with the actual date and hour to, after that, do something or don't do something(if the date is equal and so the hour, Arduino won't let someone enter to the room). But I've never programmed an Arduino and i have no idea how start it. Can you help me guys ?

P.S.:Sorry if I had some grammar error, english isn't my first language and has a time I don't practice it;

Convert each date and time into the number of minutes that have elapsed since 00:00 on 1/1/2014 (or some other suitable date and time). Each day (before the one in question) is 24 * 60 minutes. Add time (hours * 60 + minutes) to give a number you can compare with the current date and time, treated in the same way.

You need to fit your arduino with a RTC.

Mark

Thank you guys for helping me but I think I was not clear in my troubles... I actually don't have ANY idea how to code it, what functions use to access and read the archive in SD, how tell arduino to compare, how return results of this comparison... I really need a light here but thanks for all the help you gave me.

An Arduino on it own has no idea of the date or time. All it can do is elapsed (stop watch) time.

Mark

andrecgro: Thank you guys for helping me but I think I was not clear in my troubles... I actually don't have ANY idea how to code it, what functions use to access and read the archive in SD, how tell arduino to compare, how return results of this comparison... I really need a light here but thanks for all the help you gave me.

Start by going through the programs in the 'Examples' page of this site, learning and understanding how they work. Many of the people who post here started that way. Unless you want us to write your program for you. Most will charge for that service and you'll learn nothing, except how much programmers charge!

Oh ! I did not know about “examples” section, thank you ! No I really wanna learn about arduino and don’t ask to someone code for me.
Anyway, thank you for helping and adviceing me.

Another doubt... What should I do if we be in a bissextile year ? I'll have one day more in minutes...

andrecgro:
Another doubt… What should I do if we be in a bissextile year ? I’ll have one day more in minutes…

I don’t know what you mean by a bissextile year. If you mean a leap year (one that occurs every 4 years) then just do:
if year modulo 4 = 0 then add an extra day (24 * 60 Minutes) after February 28th. That will work until February 2100!