DateTime Class Reference

Wall-clock date and time based on std::chrono::system_clock. More...

#include <datetime.h>

Public Types
using	Value = std::chrono::system_clock::time_point
	Underlying time point type from the system clock.

Public Member Functions
	DateTime ()
	Default constructor. The resulting time point is epoch (uninitialized).
	DateTime (const Value &val)
	Constructs a DateTime from a system_clock time point.
	DateTime (std::tm val)
	Constructs a DateTime from a broken-down std::tm value.
	DateTime (time_t val)
	Constructs a DateTime from a time_t value.
DateTime	operator+ (const DateTime &other) const
	Returns the sum of two DateTime time points.
DateTime	operator- (const DateTime &other) const
	Returns the difference of two DateTime time points.
DateTime &	operator+= (const DateTime &other)
	Adds another DateTime's duration to this one.
DateTime &	operator-= (const DateTime &other)
	Subtracts another DateTime's duration from this one.
DateTime	operator+ (double seconds) const
	Returns a DateTime offset forward by the given number of seconds.
DateTime	operator- (double seconds) const
	Returns a DateTime offset backward by the given number of seconds.
DateTime &	operator+= (double seconds)
	Advances this DateTime forward by the given number of seconds.
DateTime &	operator-= (double seconds)
	Moves this DateTime backward by the given number of seconds.
bool	operator== (const DateTime &other) const
	Returns true if both DateTimes represent the same time point.
bool	operator!= (const DateTime &other) const
	Returns true if the DateTimes represent different time points.
bool	operator< (const DateTime &other) const
	Returns true if this DateTime is earlier than other.
bool	operator<= (const DateTime &other) const
	Returns true if this DateTime is earlier than or equal to other.
bool	operator> (const DateTime &other) const
	Returns true if this DateTime is later than other.
bool	operator>= (const DateTime &other) const
	Returns true if this DateTime is later than or equal to other.
String	toString (const char *format=DefaultFormat) const
	Formats the DateTime as a string.
	operator String () const
	Implicit conversion to String via toString().
time_t	toTimeT () const
	Converts the DateTime to a POSIX time_t value.
double	toDouble () const
	Converts the DateTime to a floating-point seconds value.
Value	value () const
	Returns the underlying system_clock time point.

Static Public Member Functions
static DateTime	now ()
	Returns a DateTime representing the current wall-clock time.
static DateTime	fromString (const String &str, const char *fmt=DefaultFormat, Error *err=nullptr)
	Parses a DateTime from a formatted string.
static DateTime	fromNow (const String &description)
	Creates a DateTime relative to the current time from a natural-language description.
static String	strftime (const std::tm &tm, const char *format=DefaultFormat)
	Formats a std::tm value using a strftime-style format string.

Static Public Attributes
static constexpr const char *	DefaultFormat = "%F %T"
	Default strftime format string ("%F %T" = "YYYY-MM-DD HH:MM:SS").

Detailed Description

Wall-clock date and time based on std::chrono::system_clock.

Wraps a system_clock time_point and provides construction from strings, time_t, and std::tm values. Supports arithmetic with other DateTime instances and with floating-point second offsets. Output formatting

Example

DateTime now = DateTime::now();
String formatted = now.toString("%Y-%m-%d %H:%M:%S");
 
// Parse from string
DateTime dt = DateTime::fromString("2025-03-15 14:30:00");
 
// Arithmetic with seconds
DateTime later = now + 3600.0;  // one hour later

uses strftime-style format strings.

Constructor & Destructor Documentation

DateTime() [1/3]

DateTime::DateTime ( const Value &  val )

inline

Constructs a DateTime from a system_clock time point.

Parameters

val	The time point value.

DateTime() [2/3]

DateTime::DateTime ( std::tm  val )

inline

Constructs a DateTime from a broken-down std::tm value.

Parameters

val	The calendar time to convert.

DateTime() [3/3]

DateTime::DateTime ( time_t  val )

inline

Constructs a DateTime from a time_t value.

Parameters

val	The POSIX time value.

Member Function Documentation

fromNow()

static DateTime DateTime::fromNow ( const String &  description )

static

Creates a DateTime relative to the current time from a natural-language description.

Parameters

description

A human-readable offset description (e.g. "2 hours ago").

Returns

The computed DateTime.

fromString()

static DateTime DateTime::fromString ( const String &  str, const char *  fmt = DefaultFormat, Error *  err = nullptr  )

inlinestatic

Parses a DateTime from a formatted string.

Parameters

str	The date/time string to parse.
fmt	The strftime-style format string (default: DefaultFormat).
err	Optional error output; set to Error::Invalid on parse failure.

Returns

The parsed DateTime, or a default-constructed DateTime on failure.

operator+()

DateTime DateTime::operator+ ( double  seconds ) const

inline

Returns a DateTime offset forward by the given number of seconds.

Parameters

seconds

Number of seconds to add.

Returns

The offset DateTime.

operator+=()

DateTime & DateTime::operator+= ( double  seconds )

inline

Advances this DateTime forward by the given number of seconds.

Parameters

seconds

Number of seconds to add.

Returns

Reference to this DateTime.

operator-()

DateTime DateTime::operator- ( double  seconds ) const

inline

Returns a DateTime offset backward by the given number of seconds.

Parameters

seconds

Number of seconds to subtract.

Returns

The offset DateTime.

operator-=()

DateTime & DateTime::operator-= ( double  seconds )

inline

Moves this DateTime backward by the given number of seconds.

Parameters

seconds

Number of seconds to subtract.

Returns

Reference to this DateTime.

strftime()

static String DateTime::strftime ( const std::tm &  tm, const char *  format = DefaultFormat  )

static

Formats a std::tm value using a strftime-style format string.

Parameters

tm	The broken-down time to format.
format	The strftime-style format string (default: DefaultFormat).

Returns

The formatted date/time string.

toDouble()

double DateTime::toDouble ( ) const

inline

Converts the DateTime to a floating-point seconds value.

Returns

Seconds since the Unix epoch as a double.

toString()

String DateTime::toString

(

const char *

format = DefaultFormat

)

const

Formats the DateTime as a string.

Parameters

format

The strftime-style format string (default: DefaultFormat).

Returns

The formatted date/time string.

toTimeT()

time_t DateTime::toTimeT ( ) const

inline

Converts the DateTime to a POSIX time_t value.

Returns

The time as seconds since the Unix epoch.

value()

Value DateTime::value ( ) const

inline

Returns the underlying system_clock time point.

Returns

The stored time point value.

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

• include/promeki/core/datetime.h