Time.h

Classes

Time -- date and time enquiry functions, with some operations. (full description)

class Time

Interface

Public Members

Time ()

Time (double jdn)

Time (uInt year, uInt month, uInt day, uInt hour=0, uInt min=0, double sec=0.0)

Time (const Time& time)

double julianDay () const

double modifiedJulianDay () const

Time& operator = (const Time& time)

double operator - (const Time& begin)

Time operator + (const double plus)

Bool operator == (const Time& other) const

Bool operator != (const Time& other) const

Bool operator > (const Time& other) const

Bool operator < (const Time& other) const

friend ostream& operator << (ostream&, const Time&)

friend istream& operator >> (istream&, Time&)

void now ()

void setDate (uInt year, uInt month, uInt day, uInt hour=0, uInt min=0, double sec=0.0)

double age ()

uInt seconds ()

uInt minutes ()

uInt hours ()

uInt dayOfMonth ()

uInt month ()

uInt year ()

uInt dayOfWeek ()

uInt dayOfYear ()

static uInt howManyDaysInMonth ()

static uInt howManyDaysInMonth (uInt month)

static uInt howManyDaysInMonth (uInt month,uInt year)

static Bool isLeapYear ()

static Bool isLeapYear (uInt year)

static Int timeZoneSeconds ()

static Double timeZoneDays ()

static String timeZoneName ()

Description

Review Status

Reviewed By:

Paul Shannon

Date Reviewed:

1995/03/01

Programs:

Tests:

tTime

This class might be better named a Date object, especially given that more accurate Time classes are going to be required.

Prerequisite

you should understand the difference between "Julian" and "modified Julian" date

Synopsis

This class provides convenient date objects for the programmer. Once constructed, they may be compared, read and written, and queried for a wide variety of re-expressions. In a typical (?) use you might create a Time object, and then query it to find out the current month, day of the week, and whether it is a leap year. You can also find out the number of seconds which have elapsed since a specific Time.

This class should not be used for very high precision work. The time from epoch (1970.0) in seconds is interconverted between computer "double" values, and some loss of accuracy might result.

Example

  Time startTime;
  Time moonLanding (1969,7,14);
  cout << "date and time of moon landing: " << moonLanding << endl;
  cout << "day of week: " << moonLanding.dayOfWeek () << endl;
  cout << "day of year: " << moonLanding.dayOfYear () << endl;
  cout << "seconds since moon landing: " << moonLanding.age () << endl;
  cout << "weeks since moon landing: " <<
     moonLanding.age () / (60 * 60 * 24 * 7) << endl;
  cout << "seconds elapsed since start: " << startTime.age () << endl;

To Do

member function 'age' might be renamed 'elapsedTime'
A reference to the source of each algorithm should be provided.

Member Description

Time ()

the default constructor returns an object with the present date and time

Time (double jdn)

Construct time with Julian day number

Time (uInt year, uInt month, uInt day, uInt hour=0, uInt min=0, double sec=0.0)

Construct Time with Gregorian calendar

seconds after the minute [0,59.999] (include milliseconds)
minutes after the hour [0,59]
hours after midnight [0,23]
day of the month [1,31]
month of the year [1,12]
year. Beware, because '94' refers to the early Christian era, not the 20th century.