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Dates in Macro

Macro has specific date-handling abiltiesabilities. Dates are a built-in data type which in fact describe both a date and a time.

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Create a new Macro icon, rename it to dates and define a date:

dd1 = 2015-03-11
print(type(dd1))
print(dd1)

Try adding a time:

dd1 = 2015-03-11 09:00

Converting numbers into dates

The date() function converts numbers into dates using the same syntax that MARS understands. For example:

• d1 = date(20150105)
• today = date(0)
• yesterday = date(-1)

This syntax can be useful if reading dates from a text file or some other source.

Again, the time will be 00:00 unless we add it. We can consider the time to be a fraction of a day:

• midday = date(20150105.5)

Use this syntax to add another variable, d2, which contains the date and time for 13:00h at 2015-03-13. Print it to check it.

Date arithmetic

When dealing with dates, the number 1 represents one day. So the expression d1 + 1 gives a date one day later than day 1. To compute the difference, in days, between two dates, it's simply:

• diff = d2 - d1

Times can be added as fractions of days, and there are some helper functions too:

• d1 = d1 + 0.5                               # add 12 hours
• d1 = d1 + hour(12)                          # hour(12) returns 0.5
• d1 = d1 + hour(23) + minute(58) + second(0) # 2 minutes to midnight