How to generate a random date and time between two dates?

Question

Don't overlook the 'date AND TIME' part though.

score 62 · Accepted Answer · answered Apr 21 '10 at 14:42

62

Time.at((date2.to_f - date1.to_f)*rand + date1.to_f)

You'll get a time object that is between two given datetimes.

answered Apr 21 '10 at 14:42

Evgeny Shadchnev

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This is a great solution however a note may be in order; you will need to convert your date to a time in order to call `to_f` on it. `Date` does not have a `to_f`. i.e. `Date.today.to_time` – rmontgomery429 Nov 03 '11 at 15:11
I need to find a way to give you another +1 - 2nd time this week I've referred to this answer! – vvohra87 Nov 27 '11 at 06:09
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For me, now at least, in 1.9.3, I can do `date1 + (date2 - date1) * rand`, and it comes out as a time. – nroose Jul 19 '13 at 01:42
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Or even simpler: `rand((DateTime.now - 3.months)..DateTime.now)` – XtraSimplicity May 10 '19 at 09:23

Jack Chu · Answer 2 · 2012-08-17T17:13:34.283

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You should be able to generate random date/times within a certain range.

now = Time.now
a_day_ago = now - 60 * 60 * 24

random_time = rand(a_day_ago..now)

# with activesupport required
up_to_a_year_ago = rand(1.year.ago..Time.now)

Your inputs need to be the Time class, or converted into one though.

You could do also do a range of time in epoch time and then use Time#at.

now = Time.now.to_i
minute_ago = (Time.now - 60).to_i
Time.at(rand(minute_ago..now))

edited Aug 17 '12 at 17:13

answered Aug 16 '12 at 21:43

Jack Chu

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In my opinion, this solution is much nicer than the currently accepted one by Evgeny. – severin Aug 17 '12 at 08:28
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One small remark, though: `1.year.ago` only works when you have *activesupport* loaded... – severin Aug 17 '12 at 08:29
Good point @severin. I included code for support with and without activesupport loaded. Also added an example for epoch time ranges. – Jack Chu Aug 17 '12 at 17:09

score 12 · Answer 3 · edited Nov 17 '15 at 01:48

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Use the rand() method.

require 'time'
t1 = Time.parse("2015-11-16 14:40:34")
t2 = Time.parse("2015-11-20 16:20:23")
puts rand(t1..t2)

edited Nov 17 '15 at 01:48

user3335966

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answered Nov 17 '15 at 01:03

SharnieIvery

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score 5 · Answer 4 · answered Apr 21 '10 at 14:39

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Use time.to_i() (see class Time) to convert your dates to integer, randomize between those two values, then reconvert to time and date with Time.at().

answered Apr 21 '10 at 14:39

Federico klez Culloca

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score 2 · Answer 5 · answered Apr 21 '10 at 14:35

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I don't know about ruby but why don't you just generate an integer and use it together with a timestamp? Then simply convert the timestamp to your desired format.

answered Apr 21 '10 at 14:35

Max Leske

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score 1 · Answer 6 · answered Aug 01 '13 at 16:03

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If you know the midpoint and the offset range on either side of the midpoint you can use my ish gem: https://github.com/spilliton/ish

mid_date.ish(:offset => 60.days)

answered Aug 01 '13 at 16:03

spilliton

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score 1 · Answer 7 · answered Jul 27 '16 at 18:04

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Time.at(rand(Time.parse('some date').to_i..Time.now.to_i))

answered Jul 27 '16 at 18:04

alebian

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Came to the same solution, the most readable option among other answers, IMHO – Artur INTECH Apr 19 '18 at 21:09

score 1 · Answer 8 · answered Oct 06 '22 at 21:29

1

Simplest way

rand(DateTime.now..3.days.from_now.to_datetime)

answered Oct 06 '22 at 21:29

Cristian Rennella

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score 0 · Answer 9 · answered Apr 21 '10 at 14:37

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Calculate the difference in for example minutes between the two dates, generate a random number between 0 and that number, and add that number of minutes to the first date.

answered Apr 21 '10 at 14:37

Maarten Ureel

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How to generate a random date and time between two dates?

9 Answers9