'Elegant way to calculate number of years between two dates in rails?

I currently have this less-than-ideal solution:

  def years_between_dates(date_from, date_to)
    ((date_to.to_time - date_from.to_time) / 1.year.seconds).floor
  end

The calculation doesn't have to be exact (w/ leap years etc), but does need to be fairly accurate and take into account months. 3.8 years should return 3 years, hence the floor.

I am converting to_time to account for both Date, Time, and DateTime.

I can't help but think there is a more succinct way of doing the above.

ruby-on-rails


Solution 1:[1]

Seems like yours is in fact the most elegant way.

Even in the definition of distance_of_time_in_words rails has: 

distance_in_minutes = ((to_time - from_time) / 60.0).round
distance_in_seconds = (to_time - from_time).round

Reference

A little better version could be:

def years_between_dates(date_from, date_to)
  ((date_to - date_from) / 365).floor
end

Solution 2:[2]

I stumbled across this looking for something else...

Am I crazy? Can't you just do:

def years_between_dates(date_from, date_to)
  date_to.year - date_from.year
end

or if you needed it to say "years" afterwards:

def years_between_dates(date_from, date_to)
  return "#{date_to.year - date_from.year} years"
end

Solution 3:[3]

if you want to get the real years between two dates, you have to consider the months and days, for example if you want to get the dates between 2010-10-01 to 2021-09-09 , the real years must be 10 years. Then you can use the next function:

  def years_between_dates(since_date, until_date)
    years = until_date.year - since_date.year
    if (until_date.month < since_date.month) ||
       (until_date.month == since_date.month && until_date.day < since_date.day)
      years -= 1
    end
    years
  end

Solution 4:[4]

Simple as:

((Time.now-1.year.ago)/1.year).abs

Sources

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Source: Stack Overflow

Solution Source
Solution 1
Solution 2 bryanfeller
Solution 3 Community
Solution 4

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