Subtract dates in Ruby and get the difference in minutes

Question

how do i subtract two different UTC dates in Ruby and then get the difference in minutes?

Thanks

Solution 1

(time1 - time2) / 60

If the time objects are string, Time.parse(time) them first

Solution 2

If you subtract two Date or DateTime objects, the result is a Rational representing the number of days between them. What you need is:

a = Date.new(2009, 10, 13) - Date.new(2009, 10, 11)
(a * 24 * 60).to_i   # 2880 minutes

or

a = DateTime.new(2009, 10, 13, 12, 0, 0) - DateTime.new(2009, 10, 11, 0, 0, 0)
(a * 24 * 60).to_i   # 3600 minutes

Solution 3

https://rubygems.org/gems/time_difference - Time Difference gem for Ruby

start_time = Time.new(2013,1)
end_time = Time.new(2014,1)
TimeDifference.between(start_time, end_time).in_minutes

Comments

[Ephemera]

Not sure if it may have changed between versions (Chubas's answer is common around the Internet), but as of version 1.9.3p364 this is the correct answer.

[Alex Korban]

I think my answer has been correct since before 1.9.3 was released :)

[Tyler Rick]

Depends if the objects in question are Time objects or Date objects. Time#- returns the number of seconds, while Date#- returns the number of days.

[utiq]

TimeDifference gem is a great solution

[Aleks]

The second part of the answer is not correct. DateTime returns number of seconds, and the accepted answer should be applied in that case - meaning (DateTime.new - DateTime.new)/60

[Alex Korban]

My answer is correct as of Ruby 2.1. I haven't tried newer versions.

[lafeber]

Almost the same but (time1 - time2) / 1.minute might be more readable.