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finding difference between two datetime values in C

Hi,

I have the following problem. I have to find the elapsed time in seconds between two given dates in the following format.

yyyyMMddhhmmss example: 20101118190541

Now i have two of these as a char [14] array and i need to find the difference in seconds between them.

Is there any C library which is portable or some algorithm i can use to calculate it ?

Infinity08

You can easily calculate the difference between two timestamps in time_t format using difftime :

http://www.cplusplus.com/reference/clibrary/ctime/difftime/

It's just a matter of getting the corresponding time_t for your timestamp. And that can be done by parsing the timestamp, filling a struct tm, and then calling mktime :

http://www.cplusplus.com/reference/clibrary/ctime/mktime/

MarioC82

ASKER

I will have a look at this and respond again.

MarioC82

ASKER

Hi i have a quick question, with the above date format would something like this work to populate the tm struct.

fromDate is a char[14] array containing the date.

scanf(fromDate, "%.4s%.2s%.2s%.2s%.2%.2", t->tm_year, t->tm_mon, t->tm_mday, t->tm_hour, t->tm_min, t->tm_wday);

However i dont seem to get the values to pass i only get current date still.

masheik

You are missing %s in sscanf

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Infinity08

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MarioC82

ASKER

Thanks Infinity08.