SystemClockClass Class Reference

#include <SystemClock.h>

Public Types
using	CheckTimeZoneOffset = Delegate< void(time_t systemTime)>
	Optional callback which can be used to automate handling of timezone changes. More...

Public Member Functions
time_t	now (TimeZone timeType=eTZ_Local) const
	Get the current date and time. More...
bool	setTime (time_t time, TimeZone timeType)
	Set the system clock's time. More...
String	getSystemTimeString (TimeZone timeType=eTZ_Local) const
	Get current time as a string. More...
void	setTimeZoneOffset (int seconds)
	Sets the local time zone offset. More...
void	setTimeZone (float localTimezoneOffset)
	Set the local time zone offset in hours. More...
void	setTimeZone (const DateTime::ZoneInfo &zoneInfo)
	Set current time zone information. More...
const DateTime::ZoneInfo &	getTimeZone () const
	Get current time zone information. More...
int	getTimeZoneOffset () const
	Get the current time zone offset. More...
bool	isSet () const
	Determine if setTime() has been called yet. More...
void	onCheckTimeZoneOffset (CheckTimeZoneOffset callback)
	Set/clear a callback which is invoked whenever local time is queried. More...

Member Typedef Documentation

CheckTimeZoneOffset

using SystemClockClass::CheckTimeZoneOffset = Delegate<void(time_t systemTime)>

Optional callback which can be used to automate handling of timezone changes.

Parameters

systemTime

The current system time

Although the timezone offset only changes twice a year, when it does change the corresponding offset should be updated promptly.

setTimeZoneOffset() is typically called when updating via real-time clock chip or NTP, but this can still leave a considerable gap during which the local time will be wrong.

The callback should check the provided systemTime and determine if the time zone offset requires changing and, if so, call setTimeZoneOffset(). One way to make this efficient is to cache the time_t value for the next change, rather than attemtpting to compute the offset on every call.

Member Function Documentation

getSystemTimeString()

String SystemClockClass::getSystemTimeString

(

TimeZone

timeType = eTZ_Local

)

const

Get current time as a string.

Parameters

timeType

Time zone to present time as, i.e. return local or UTC time

Return values

String

Current time in format: dd.mm.yy hh:mm:ss

getTimeZone()

const DateTime::ZoneInfo& SystemClockClass::getTimeZone ( ) const

inline

Get current time zone information.

Return values

ZoneInfo

getTimeZoneOffset()

int SystemClockClass::getTimeZoneOffset ( ) const

inline

Get the current time zone offset.

Return values

int	Offset in seconds from UTC

isSet()

bool SystemClockClass::isSet ( ) const

inline

Determine if setTime() has been called yet.

Note

Indicates whether time returned can be relied upon

now()

time_t SystemClockClass::now

(

TimeZone

timeType = eTZ_Local

)

const

Get the current date and time.

Parameters

timeType

Time zone to use (UTC / local)

Return values

DateTime

Current date and time

onCheckTimeZoneOffset()

void SystemClockClass::onCheckTimeZoneOffset ( CheckTimeZoneOffset  callback )

inline

Set/clear a callback which is invoked whenever local time is queried.

Note

This callback is only invoked when now() is called.

setTime()

bool SystemClockClass::setTime	(	time_t	time,
		TimeZone	timeType
	)

Set the system clock's time.

Parameters

time	Unix time to set clock to (quantity of seconds since 00:00:00 1970-01-01)
timeType	Time zone of Unix time, i.e. is time provided as local or UTC?

Note

System time is always stored as UTC time. If setting using the value retrieved from a time server using NTP, specify eTZ_UTC. If passing a local value using eTZ_Local, ensure that the time zone has been set correctly as it will be converted to UTC before storing.

setTimeZone() [1/2]

void SystemClockClass::setTimeZone ( const DateTime::ZoneInfo &  zoneInfo )

inline

Set current time zone information.

Parameters

zoneInfo

Contains offset plus string formatting information

setTimeZone() [2/2]

void SystemClockClass::setTimeZone ( float  localTimezoneOffset )

inline

Set the local time zone offset in hours.

Parameters

localTimezoneOffset

Offset from UTC of local time zone in hours

Return values

bool	true on success, false if value out of range

Note

Values for local standard time may exceed +/- 12 For example, Pacific/Kiritimati has a 14-hour offset (in 2024).

setTimeZoneOffset()

void SystemClockClass::setTimeZoneOffset ( int  seconds )

inline

Sets the local time zone offset.

Parameters

seconds

Offset from UTC of local time zone in seconds

See also

See setTimeZone().

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The documentation for this class was generated from the following file:

• SystemClock.h