Dates and Times

The DateTime class provided by the Ruby standard library is used to represent most dates and times. If you expect to use any methods that get or set dates, you will need to require the date module at the top of your script file.

require 'date'

Using the DateTime Class

The base unit of the DateTime class is 1 day:

puts DateTime.now
⇒ "2024-01-01T00:00:00+00:00"

puts DateTime.now + 1
⇒ "2024-01-02T00:00:00+00:00"

The DateTime class is convenient for dealing with extended period simulations, but when dealing with hours and minutes you may find it more convenient to use Ruby's Time class instead. The Time class uses 1 second as it's base unit:

puts Time.now
⇒ "2024-01-01T00:00:00+00:00"

puts Time.now + 60
⇒ "2024-01-01T00:01:00+00:00"

To convert from a DateTime to a Time, use <DateTime>.to_time, and to convert back use <Time>.to_datetime. Workgroup methods expecting a DateTime will not work with Time.

Creating new DateTime objects

You can create DateTime objects using the new method:

puts DateTime.new(2001, 01, 01, 12, 45)
⇒ "2024-01-01T12:45:00+00:00"

You can also get the current time:

right_now = DateTime.now

Overriding Display Behaviour

By default, when a DateTime object is converted to a string (e.g. via the puts method) the output will appear like this:

puts commit.date
⇒ "2023-12-25T16:58:50+01:00"

To customise the output you can use strftime:

puts commit.strftime("%F %T")
⇒ "2023-12-25 17:00:37"

For the best compatibility with other systems, you should use the <DateTime>.iso8601 method which returns a string in a standard format.

puts commit.iso8601
⇒ "2023-12-25T10:36:50+01:00"

Dates and Times in Results

Simulations can use absolute or relative times, so the following convention is used:

• Absolute times are represented as a Ruby DateTime object
• Relative times are represented as a negative double (time in seconds)