Count number of days between two dates

问题:

How do I count the number of days between these two dates?

start_date = Date.parse "2012-03-02 14:46:21 +0100" end_date =  Date.parse "2012-04-02 14:46:21 +0200" 

回答1:

With the Date (and DateTime) classes you can do (end_date - start_date).to_i to get the number of days difference.

回答2:

Assuming that end_date and start_date are both of class ActiveSupport::TimeWithZone in Rails, then you can use:

(end_date.to_date - start_date.to_date).to_i 

回答3:

Rails has some built in helpers that might solve this for you. One thing to keep in mind is that this is part of the Actionview Helpers, so they wont be available directly from the console.

Try this

     "about 1 month" 

回答4:

I kept getting results in seconds, so this worked for me:

(Time.now - self.created_at) / 86400 

回答5:

None of the previous answers (to this date) gives the correct difference in days between two dates.

The one that comes closest is by thatdankent. A full answer would convert to_i and then divide:

(Time.now.to_i - 23.hours.ago.to_i) / 1.day >> 0  (Time.now.to_i - 25.hours.ago.to_i) / 1.day >> 1  (Time.now.to_i - 1.day.ago.to_i) / 1.day >> 1 

In the question's specific example, one should not parse to Date if the time passed is relevant. Use Time.parse instead.

回答6:

to get the number of days in a time range (just a count of all days)

(start_date..end_date).count (start_date..end_date).to_a.size #=> 32 

to get the number of days between 2 dates

(start_date...end_date).count (start_date...end_date).to_a.size #=> 31 

回答7:

To have the number of whole days between two dates (DateTime objects):

((end_at - start_at).to_f / 1.day).floor 

回答8:

def business_days_between(date1, date2)   business_days = 0   date = date2   while date > date1    business_days = business_days + 1 unless date.saturday? or date.sunday?    date = date - 1.day   end   business_days end 

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