tm - cppreference.com (original) (raw)
Structure holding a calendar date and time broken down into its components.
Contents
[edit] Member objects
| int tm_sec | seconds after the minute – [0, 61](until C99)[0, 60](since C99)[note 1] (public member object) |
|---|---|
| int tm_min | minutes after the hour – [0, 59] (public member object) |
| int tm_hour | hours since midnight – [0, 23] (public member object) |
| int tm_mday | day of the month – [1, 31] (public member object) |
| int tm_mon | months since January – [0, 11] (public member object) |
| int tm_year | years since 1900 (public member object) |
| int tm_wday | days since Sunday – [0, 6] (public member object) |
| int tm_yday | days since January 1 – [0, 365] (public member object) |
| int tm_isdst | Daylight Saving Time flag. The value is positive if DST is in effect, zero if not and negative if no information is available (public member object) |
[edit] Notes
The Standard mandates only the presence of the aforementioned members in either order. The implementations usually add more data-members to this structure.
- ↑ Range allows for a positive leap second. Two leap seconds in the same minute are not allowed (the C89 range 0..61 was a defect)
[edit] Example
#include <stdio.h> #include <time.h> int main(void) { struct tm start = {.tm_year = 2022 - 1900, .tm_mday = 1}; mktime(&start); printf("%s", asctime(&start)); // note implicit trailing '\n' }
Output:
[edit] References
C23 standard (ISO/IEC 9899:2024):
7.27.1/3 Components of time (p: TBD)
C17 standard (ISO/IEC 9899:2018):
7.27.1/3 Components of time (p: 284)
C11 standard (ISO/IEC 9899:2011):
7.27.1/3 Components of time (p: 388)
C99 standard (ISO/IEC 9899:1999):
7.23.1/3 Components of time (p: 338)
C89/C90 standard (ISO/IEC 9899:1990):
4.12.1 Components of time