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I have char date[] = "2011-04-01"; How it convert to timestamp in C or C++ ?

golabb
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    Maybe this answer can help: http://stackoverflow.com/questions/1002542/how-to-convert-datetime-to-unix-timestamp-in-c – MD Sayem Ahmed Apr 22 '11 at 10:01
  • Your title says C, your question says C or C++, and you tagged just C++. Are you programming in C, or programming in C++? – Puppy Apr 22 '11 at 10:36

2 Answers2

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Warning: strptime is a POSIX-function (may not be available through time.h on OS "Windows" platform).

#include <time.h>

struct tm time;
strptime("2011-04-01", "%Y-%m-%d", &time);
time_t loctime = mktime(&time);  // timestamp in current timezone
time_t gmttime = timegm(&time);  // timestamp in GMT
Nikolai Sokolovsky
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blaze
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    Not fully initializing/assigning `time` can be a problem: "unspecified ... will update the current contents of the structure or overwrite all contents of the structure". Suggest `struct tm time = {0};` and use `time->isdst == -1;`. – chux - Reinstate Monica Jan 26 '17 at 18:16
  • Where is it neccesary to use: "time->isdst == -1;" ? – Cristian Mar 21 '18 at 16:30
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Try this:

char date[] = "2011-04-01";
date[4] = date[7] = '\0';
struct tm tmdate = {0};
tmdate.tm_year = atoi(&date[0]) - 1900;
tmdate.tm_mon = atoi(&date[5]) - 1;
tmdate.tm_mday = atoi(&date[8]);
time_t t = mktime( &tmdate );
Blazes
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  • Note that this solutions assume that `"2011-04-01"` is the _local_ date and the DST is _not_ in effect as `tmdate.tm_mday == 0`. Thus `time_t t` may be 1 hour off from midnight. – chux - Reinstate Monica Jan 26 '17 at 18:09