Get random time objects between certain hours in Rails - ruby-on-rails

Question

I would want a method that:
def time_between(from, to)
***
end
time_between 10.am.of_today, 3.pm.of_today # => 1pm Time object
time_between 10.am.of_today, 3.pm.of_today # => 3pm Time object
time_between 10.am.of_today, 3.pm.of_today # => 10:30am Time object
# I mean random
There are two questions here: how to implement ***? and how to implement x.pm.of_today?

Answer 1

ruby 1.9.3
require 'rubygems'
require 'active_support/all'
def random_hour(from, to)
(Date.today + rand(from..to).hour + rand(0..60).minutes).to_datetime
end
puts random_hour(10, 15)

Answer 2

This is a first try:
def time_between(from, to)
today = Date.today.beginning_of_day
(today + from.hours)..(today + to.hours).to_a.sample
end
Although it works like:
time_between(10, 15) # => a random time between 10 am and 3 pm
I think is enough, but I'll be open for better solutions.

Answer 3

To get the random time slot you will need to calculate the distance between the two times. Get a random value with that distance span. And finally add it to your from time.
Something like: (but I am not going to test it)
def time_between(from, to)
if from > to
time_between(to, from)
else
from + rand(to - from)
end
end
As for creating a DSL for time. You could look at how Rails does it. But to get something like what you are wanting. Just create a class that represents the hours in the day. Instantiate it with the am or pm call on a Fixnum. Then write the methods for of_today (and any others that you would want).
class Fixnum
def am
TimeWriter.new(self)
end
def pm
TimeWriter.new(self + 12)
end
end
class TimeWriter
MINUTES_IN_HOUR = 60
SECONDS_IN_MINUTE = 60
SECONDS_IN_HOUR = MINUTES_IN_HOUR * SECONDS_IN_MINUTE
def initialize hours
#hours = hours
end
def of_today
start_of_today + (hours * SECONDS_IN_HOUR)
end
private
attr_reader :hours
def start_of_today
now = Time.now
Time.new(now.year, now.month, now.day, 0, 0)
end
end
You should add some error handling for hours more than 24.

Answer 4

This code respects minutes and hours as input.
require 'rubygems'
require 'active_support/all'
def random_time(from, to)
from_arr = from.split(':')
to_arr = to.split(':')
now = Time.now
rand(Time.new(now.year, now.month, now.day, from_arr[0], rom_arr[1])..Time.new(now.year, now.month, now.day, to_arr[0], to_arr[1]))
end
puts random_time('09:15', '18:45')
Another short way to do the same:
require 'rubygems'
require 'active_support/all'
def random_time(from, to)
now = Time.now
rand(Time.parse(now.strftime("%Y-%m-%dT#{from}:00%z"))..Time.parse(now.strftime("%Y-%m-%dT#{to}:00%z")))
end
puts random_time('09:15', '18:45')