Dates, Times, and the Calendar Package

With a new Calendar package, Maple 2018 makes it easier to work with dates and times, such as analyzing time-dependent data, or calculating the flight duration to your next conference.  

Maple 2018 includes new data structures that represent dates and times. There are numerous functions for working with dates and times, including fundamental operations such as date arithmetic and more advanced functionality for working with Calendars. Existing packages such as Finance also support the new Date object. 

Dates, Times, and Clocks 

• New objects representing dates, times, and clocks were introduced in Maple 2018.
• The Now method for a clock creates a Time object representing the current time according to the indicated clock.  

>	now := Now( SystemUTCClock );

• From a given Time object, you can create a corresponding Date object, as follows.

>	today := Date( now );

• Or, more simply, use the Date constructor without arguments.

>	today := Date();

• Various fields of the Date object are accessible.

>	Year( today );

>	DayOfMonth( today );

>	Minute( today );

• Arithmetic with Date and Time objects is builtin.
• To compute the amount of time between two dates represented as Date objects, just subtract them.

>	d1 := Date( 2017, 12, 25 );

>	d2 := Date( 2000, 12, 25 );

>	t := d1 - d2;

>	convert( t, 'units', 'days' );

(For more control over the units used in computing the time between two dates, use the DateDifference command in the Calendar package).

• In fact, any affine combination of Date objects results in an expression involving units of time.
• A convex combination of Date objects results in another Date object.  For instance, to compute the average value of two Date objects, you can use an expression such as the following one.

>	( d1 + d2 ) / 2;

• You can specify a date in a particular time zone by using the timezone option to the Date constructor. Suppose, for example, that a flight leaves Toronto at p.m. on March 12, 2007, and arrives in Paris at a.m. on March 13.

>	depart := Date( 2007, 3, 12, 20, 44, 'timezone' = "America/Toronto" );

>	arrive := Date( 2007, 3, 13, 9, 3, 'timezone' = "Europe/Paris" );

• To compute the flight time, simply subtract the two dates.

>	flight_time := arrive - depart;

>	convert( flight_time, 'units', 'hours' );