Rails Duration cheat sheet

duration-cheat-sheet.md

I constantly find it hard to know how to express a duration, but once I figure it out, it's abundantly clear. So here's some helpful examples.

There are multiple methods that do the same thing, to help you express the intent the way that makes sense to you.

Past: ago/before/until

1.week.ago           # same as Time.current - 1.week
1.week.before(@date) # same as @date - 1.week

I can't think of a use for until

Future: from_now/after/since

1.week.from_now     # same as Time.current + 1.week
1.week.after(@date) # same as @date + 1.week

I can't think of a use for since

See: Duration reference

Bonus: Range#step

Loop through each week:

(@from..@to).step(7).each {} # Assuming magic number of 7 days in week