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2 Library Reference
AVR Libc Library Reference
2 <time.h>: Time
2.3 Functions
2.3.16 void set_dst
void set_dst(int(*)(const time_t *, int32_t *))

AVRLibc

AVR Libc
1 User Manual
2 Library Reference
AVR Libc Library Reference
- 2 <alloca.h>: Allocate space in the stack
- 2 <assert.h>: Diagnostics
- 2 <avr/boot.h>: Bootloader Support Utilities
- 2 <avr/cpufunc.h>: Special AVR CPU functions
- 2 <avr/eeprom.h>: EEPROM handling
- 2 <avr/fuse.h>: Fuse Support
- 2 <avr/interrupt.h>: Interrupts
- 2 <avr/io.h>: AVR device-specific IO definitions
- 2 <avr/lock.h>: Lockbit Support
- 2 <avr/pgmspace.h>: Program Space Utilities
- 2 <avr/power.h>: Power Reduction Management
- 2 <avr/sfr_defs.h>: Special function registers
- 2 <avr/signature.h>: Signature Support
- 2 <avr/sleep.h>: Power Management and Sleep Modes
- 2 <avr/version.h>: avr-libc version macros
- 2 <avr/wdt.h>: Watchdog timer handling
- 2 <compat/deprecated.h>: Deprecated items
- 2 <compat/ina90.h>: Compatibility with IAR EWB 3.x
- 2 <ctype.h>: Character Operations
- 2 <errno.h>: System Errors
- 2 <inttypes.h>: Integer Type conversions
- 2 <math.h>: Mathematics
- 2 <setjmp.h>: Non-local goto
- 2 <stdint.h>: Standard Integer Types
- 2 <stdio.h>: Standard IO facilities
- 2 <stdlib.h>: General utilities
- 2 <string.h>: Strings
- 2 <time.h>: Time
  - 2.1 Enumerations
  - 2.2 Typedefs
  - 2.3 Functions
    - 2.3.1 time_t time
      time_t time(time_t *timer)
    - 2.3.2 int32_t difftime
      int32_t difftime(time_t time1, time_t time0)
    - 2.3.3 time_t mktime
      time_t mktime(struct tm *timeptr)
    - 2.3.4 time_t mk_gmtime
      time_t mk_gmtime(const struct tm *timeptr)
    - 2.3.5 struct tm* gmtime
      struct tm* gmtime(const time_t *timer)
    - 2.3.6 void gmtime_r
      void gmtime_r(const time_t *timer, struct tm *timeptr)
    - 2.3.7 struct tm* localtime
      struct tm* localtime(const time_t *timer)
    - 2.3.8 void localtime_r
      void localtime_r(const time_t *timer, struct tm *timeptr)
    - 2.3.9 char* asctime
      char* asctime(const struct tm *timeptr)
    - 2.3.10 void asctime_r
      void asctime_r(const struct tm *timeptr, char *buf)
    - 2.3.11 char* ctime
      char* ctime(const time_t *timer)
    - 2.3.12 void ctime_r
      void ctime_r(const time_t *timer, char *buf)
    - 2.3.13 char* isotime
      char* isotime(const struct tm *tmptr)
    - 2.3.14 void isotime_r
      void isotime_r(const struct tm *, char *)
    - 2.3.15 size_t strftime
      size_t strftime(char *s, size_t maxsize, const char *format, const struct tm *timeptr)
    - 2.3.16 void set_dst
      void set_dst(int(*)(const time_t *, int32_t *))
    - 2.3.17 void set_zone
      void set_zone(int32_t)
    - 2.3.18 void set_system_time
      void set_system_time(time_t timestamp)
    - 2.3.19 void system_tick
      void system_tick(void)
    - 2.3.20 uint8_t is_leap_year
      uint8_t is_leap_year(int16_t year)
    - 2.3.21 uint8_t month_length
      uint8_t month_length(int16_t year, uint8_t month)
    - 2.3.22 uint8_t week_of_year
      uint8_t week_of_year(const struct tm *timeptr, uint8_t start)
    - 2.3.23 uint8_t week_of_month
      uint8_t week_of_month(const struct tm *timeptr, uint8_t start)
    - 2.3.24 struct week_date* iso_week_date
      struct week_date* iso_week_date(int year, int yday)
    - 2.3.25 void iso_week_date_r
      void iso_week_date_r(int year, int yday, struct week_date *)
    - 2.3.26 uint32_t fatfs_time
      uint32_t fatfs_time(const struct tm *timeptr)
    - 2.3.27 void set_position
      void set_position(int32_t latitude, int32_t longitude)
    - 2.3.28 int16_t equation_of_time
      int16_t equation_of_time(const time_t *timer)
    - 2.3.29 int32_t daylight_seconds
      int32_t daylight_seconds(const time_t *timer)
    - 2.3.30 time_t solar_noon
      time_t solar_noon(const time_t *timer)
    - 2.3.31 time_t sun_rise
      time_t sun_rise(const time_t *timer)
    - 2.3.32 time_t sun_set
      time_t sun_set(const time_t *timer)
    - 2.3.33 double solar_declination
      double solar_declination(const time_t *timer)
    - 2.3.34 int8_t moon_phase
      int8_t moon_phase(const time_t *timer)
    - 2.3.35 unsigned long gm_sidereal
      unsigned long gm_sidereal(const time_t *timer)
    - 2.3.36 unsigned long lm_sidereal
      unsigned long lm_sidereal(const time_t *timer)
  - 2.4 Defines
- 2 <util/atomic.h> Atomically and Non-Atomically Executed Code Blocks
- 2 <util/crc16.h>: CRC Computations
- 2 <util/delay.h>: Convenience functions for busy-wait delay loops
- 2 <util/delay_basic.h>: Basic busy-wait delay loops
- 2 <util/parity.h>: Parity bit generation
- 2 <util/setbaud.h>: Helper macros for baud rate calculations
- 2 <util/twi.h>: TWI bit mask definitions
- 2.1 Structures
3 Example Projects
4 Files

2.3.16 void set_dst

void set_dst(int(*)(const time_t *, int32_t *))

Specify the Daylight Saving function.

The Daylight Saving function should examine its parameters to determine whether Daylight Saving is in effect, and return a value appropriate for tm_isdst.

Working examples for the USA and the EU are available..

 #include <util/eu_dst.h>

for the European Union, and

 #include <util/usa_dst.h>

for the United States

If a Daylight Saving function is not specified, the system will ignore Daylight Saving.

The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.