Question

Is there a way to iterate over a Time range in Ruby, and set the delta?

Here is an idea of what I would like to do:

for hour in (start_time..end_time, hour)     hour #=> Time object set to hour end 

You can iterate over the Time objects, but it returns every second between the two. What I really need is a way to set the offset or delta (such as minute, hour, etc.)

Is this built in to Ruby, or is there a decent plugin available?

Answer 1

Prior to 1.9, you could use Range#step:

(start_time..end_time).step(3600) do |hour|   # ... end 

However, this strategy is quite slow since it would call Time#succ 3600 times. Instead, as pointed out by dolzenko in his answer, a more efficient solution is to use a simple loop:

hour = start_time while hour < end_time   # ...   hour += 3600 end 

If you’re using Rails you can replace 3600 with 1.hour, which is significantly more readable.