The Ruby Way: Solutions and Techniques in Ruby Programming, Second Edition

7.16. Adding Intervals to Date/Time Values

We can obtain a new time by adding an interval to a specified time. The number is interpreted as a number of seconds.

t0 = Time.now
t1 = t0 + 60         # Exactly one minute past t0
t2 = t0 + 3600       # Exactly one hour past t0
t3 = t0 + 86400      # Exactly one day past t0

The function dhms2sec (defined in section 7.6 “Converting Between Seconds and Larger Units” earlier in the chapter) might be helpful here. Recall that the hours, minutes, and seconds all default to 0.

t4 = t0 + dhms2sec(5,10)       # Ahead 5 days, 10 hours
t5 = t0 + dhms2sec(22,18,15)   # Ahead 22 days, 18 hrs, 15 min
t6 = t0 - dhms2sec(7)          # Exactly one week ago

Don’t forget that we can move backward in time by subtracting. This is shown in the calculation ...