unix longtime 2099

[kasavazala]

Can anyone tell me how to get the unix long time for the date 01/01/2099. when i am trying to use mktime from a c program, I am getting -1.
this is the chunk of code i am using
struct tm *tm;
time_t l;
int i;
long ptm;

l = time(&i);
tm = localtime(&i);

tm->tm_year=2099-1900;
tm->tm_mon=0;
tm->tm_mday=1;
tm->tm_hour=0;
tm->tm_sec=0;
tm->tm_min=0;

ptm = mktime(tm);

printf("%ld\n",ptm);

is giving me -1.

thanks in advance.

 

[Annihilannic]

What operating system are you on?

On Solaris for example, from the mktime() man page:

[tt] The tm_year member must be for year 1901 or later. Calendar
times before 20:45:52 UTC, December 13, 1901 or after
03:14:07 UTC, January 19, 2038 cannot be represented. Port-
able applications should not try to create dates before
00:00:00 UTC, January 1, 1970 or after 00:00:00 UTC, January
1, 2038.[/tt]



Annihilannic.

 

[usige]

The reason you are getting -1 is mktime return -1 if it cannot convert the tm struct to an epoch time. In other words -1 means there is no epoch time representation of 1-Jan-2099 beacuse it would overflow the 32-bit int used to store epoch time. Annihilannic's post gives the acceptable date ranges. I have never seen a unix system that allows 2099 to be converted w/ standard time functions. That being the case I know of no way for mktime to decode that date.

Sorry I don't have a better answer for you.