Question

How would I generate a random date that has to be between two other given dates?

The function’s signature should be something like this:

random_date('1/1/2008 1:30 PM', '1/1/2009 4:50 AM', 0.34)                    ^                       ^          ^              date generated has  date generated has  a random number             to be after this    to be before this 

and would return a date such as: 2/4/2008 7:20 PM

Answer 1

Convert both strings to timestamps (in your chosen resolution, e.g. milliseconds, seconds, hours, days, whatever), subtract the earlier from the later, multiply your random number (assuming it is distributed in the range [0, 1]) with that difference, and add again to the earlier one. Convert the timestamp back to date string and you have a random time in that range.

Python example (output is almost in the format you specified, other than 0 padding – blame the American time format conventions):

import random import time      def str_time_prop(start, end, time_format, prop):     """Get a time at a proportion of a range of two formatted times.      start and end should be strings specifying times formatted in the     given format (strftime-style), giving an interval [start, end].     prop specifies how a proportion of the interval to be taken after     start.  The returned time will be in the specified format.     """      stime = time.mktime(time.strptime(start, time_format))     etime = time.mktime(time.strptime(end, time_format))      ptime = stime + prop * (etime - stime)      return time.strftime(time_format, time.localtime(ptime))   def random_date(start, end, prop):     return str_time_prop(start, end, '%m/%d/%Y %I:%M %p', prop)      print(random_date("1/1/2008 1:30 PM", "1/1/2009 4:50 AM", random.random()))