Date-Time

The date-time library maintains the current date-time information in UTC format. The option CONFIG_DATE_TIME_UPDATE_INTERVAL_SECONDS determines the frequency with which the library updates the date-time information.

The information is fetched in the following prioritized order:

  1. The library checks if the current date-time information is valid and relatively new. If the date-time information currently set in the library was obtained sometime during the interval set by CONFIG_DATE_TIME_UPDATE_INTERVAL_SECONDS, the library does not fetch new date-time information. In this way, unnecessary update cycles are avoided.

  2. If the aforementioned check fails, the library requests time from the onboard modem of nRF9160.

  3. If the time information obtained from the onboard modem of nRF9160 is not valid, the library requests time from NTP servers.

  4. If the NTP time request does not succeed, the library tries to request time information from several other NTP servers, before it fails.

The date_time_set() function can be used to obtain the current date-time information from external sources independent of the internal date-time update routine. Time from GPS can be such an external source.

To get date-time information from the library, either call the date_time_uptime_to_unix_time_ms() function or the date_time_now() function. See the API documentation for more information on these functions.

Note

The first date-time update cycle (after boot) does not occur until the time set by the CONFIG_DATE_TIME_UPDATE_INTERVAL_SECONDS has elapsed. It is recommended to call the date_time_update() function after the device has connected to LTE, to get the initial date-time information.

Configuration

CONFIG_DATE_TIME_UPDATE_INTERVAL_SECONDS

Configure this option to control the frequency with which the library fetches the time information.

API documentation

Header file: include/date_time.h
Source files: lib/date_time/src/
group date_time

Library that maintains the current date time UTC which can be fetched in order to timestamp data.

Typedefs

typedef void (*date_time_evt_handler_t)(const struct date_time_evt *evt)

Date time library asynchronous event handler.

Parameters

  • [in] evt: The event and any associated parameters.

Enums

enum date_time_evt_type

Date time notification event types used to signal the application.

Values:

enumerator DATE_TIME_OBTAINED_MODEM

Date time library has obtained valid time from the modem.

enumerator DATE_TIME_OBTAINED_NTP

Date time library has obtained valid time from NTP servers.

enumerator DATE_TIME_OBTAINED_EXT

Date time library has obtained valid time from external source.

enumerator DATE_TIME_NOT_OBTAINED

Date time library does not have valid time.

Functions

int date_time_set(const struct tm *new_date_time)

Set the current date time.

Note

See http://www.cplusplus.com/reference/ctime/tm/ for accepted input format.

Return

0 If the operation was successful.

Return

-EINVAL If a member of the passing variable new_date_time does not adhere to the tm structure format.

Parameters

  • [in] new_date_time: Pointer to a tm structure.

int date_time_uptime_to_unix_time_ms(int64_t *uptime)

Get the date time UTC when the passing variable uptime was set. This function requires that k_uptime_get() has been called on the passing variable uptime prior to the function call.

Warning

If the function fails, the passed in variable retains its old value.

Return

0 If the operation was successful.

Return

-ENODATA If the library does not have a valid date time UTC.

Return

-EINVAL If the passing variable is too large or already converted.

Parameters

  • [inout] uptime: Pointer to a previously set uptime.

int date_time_now(int64_t *unix_time_ms)

Get the current date time UTC.

Warning

If the function fails, the passed in variable retains its old value.

Return

0 If the operation was successful.

Return

-ENODATA If the library does not have a valid date time UTC.

Parameters

  • [out] unix_time_ms: Pointer to a variable to store the current date time UTC.

void date_time_register_handler(date_time_evt_handler_t evt_handler)

Register an event handler for Date time library events.

Warning

The library only allows for one event handler to be registered at a time. A passed in event handler in this function will overwrite the previously set event handler.

Parameters

  • evt_handler: Event handler. Handler is de-registered if parameter is NULL.

int date_time_update_async(date_time_evt_handler_t evt_handler)

Asynchronous update of internal date time UTC. This function initiates a date time update regardless of the internal update interval. If an event handler is provided it will be updated with library events, accordingly.

Return

0 If the operation was successful.

Parameters

  • evt_handler: Event handler. If the passed in pointer is NULL the previous registered event handler is not de-registered. This means that library events will still be received in the previously registered event handler.

int date_time_clear(void)

Clear the current date time held by the library.

Return

0 If the operation was successful.

int date_time_timestamp_clear(int64_t *unix_timestamp)

Clear a timestamp in unix time ms.

Return

0 If the operation was successful.

Parameters

  • [inout] unix_timestamp: Pointer to a unix timestamp.

struct date_time_evt
#include <date_time.h>

Struct with data received from the Date time library.

Public Members

enum date_time_evt_type type

Type of event.