1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Time in Minutes

  1. Mar 17, 2010 #1
    Hey all,

    I have a quick question about converting a difference between 2 times into minutes.
    I am modelling a 24 hour clock. The time 900 represents the time 09:00 and 1500 represents the time 15:00. If I subtract the two I get a difference of 600. If I want to convert this to minutes I would write (600/100)*60. There's my answer, but I can't seem to get my head round what (600/100) is doing. Why do I need to divide it by 100?

    This question was brought to you by an idiot.
  2. jcsd
  3. Mar 17, 2010 #2
    Because you represent hours as "hours*100", so to get "hours" back you need to divide by 100.
  4. Mar 17, 2010 #3
    12 and 24 hour clocks use the format: HH:MM, where H is an hour digit and M is a minute digit. Don't subtract the two times like that.
    15:00 - 09:00 = 6:00
    Six hours.
    There's 60 minutes in an hour, so multiply this by 60 minutes per hour.

    [tex]6 hour*\frac{60 minute}{1 hour} = 360 minutes[/tex]

    You don't need to divide by 100.

    Let's say you were looking at the difference between 7:00 and 8:45. Since there's 60 minutes in an hour, you can look at it like this.

    You need 60 minutes to reach 8:00 from 7:00. Then you need an additional 45 minutes to reach 8:45.

    Look at the difference between 7:00 and 10:30 now.
    You need 3 hours (10-7) and 30 minutes (30-0) to reach the end time. To get this into minutes, just multiply the 3 hours by 60 minutes per hour = (180 minutes), and add to 30 minutes to obtain 210 minutes.

    Hope this helps. Remember, there are no stupid questions; only answers can be stupid.
  5. Mar 17, 2010 #4
    Thanks a lot for the answers. Makes sense now :smile:

    The reason I had to do it like that however is for computer programming. Unfortunately coding a program to understand HH:MM is more complicated than doing HHMM-HHMM, though the former is so much easier to do in our heads :tongue:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Time in Minutes
  1. Time and DIstance (Replies: 1)

  2. Calculating Time? (Replies: 0)

  3. Time equals ? (Replies: 6)