How to create a hour clock calculation to the next quater hour

[ipitech]

I am trying to formulate a spreadsheet that alllows me to arrive at
entering a start time(in) (9:12) and a finish time(out) (9:43) having a result of 30 mins.
I am able to arrive at a calculation subtracting the time out from time in to arrive at a given time, but I want to achieve the most of the time worked to the next quater hour.
What calculation should I use?

 

[MrVillareal]

Hi can you give sample result?

 

[ipitech]

I have been requested to provide a detailed account of the time our vehicles are onsite. A truck arrives on a site at 9:12 and leaves at 9:40. this would represent that the vehicle was on site for 28 mins. As we are unable to bill our time other than by the quarter hour the time should reflect the time from 9:00 to 9:45 which would account for a total of 45 mins.
Does this help?

 

[bebo021999]

I have been requested to provide a detailed account of the time our vehicles are onsite. A truck arrives on a site at 9:12 and leaves at 9:40. this would represent that the vehicle was on site for 28 mins. As we are unable to bill our time other than by the quarter hour the time should reflect the time from 9:00 to 9:45 which would account for a total of 45 mins.
Does this help?

Try this:

A1: Arrival time

A2: Leaving time

A3: Time billing: = CEILING(A2-A1,45/1440)

Does it help?

 

[ipitech]

Using that calculation I obtained the following results;
(1) 9:01 am to 9:43 am = 0.45
(2) 9:02 am to 9:51 am = 1:30

The latter of the two would appear to be incorrect...

By the way thank you very much for your help...

 

[bebo021999]

Using that calculation I obtained the following results;
(1) 9:01 am to 9:43 am = 0.45
(2) 9:02 am to 9:51 am = 1:30
The latter of the two would appear to be incorrect...
By the way thank you very much for your help...

My previous formular to round up the difference to pack of 45 mins.
Finally, Is this meet your idea: 9:01 arrival round down to 9:00; 9:51 round up to 10:00, ...etc...? the difference should be 45 mins*n?

 

[ipitech]

I changed the formula to =ceiling(A2-A1,15/1440) and that seem to resolve the conflict...
Thank you very much for your time...