Matching two objects based on Time difference

Hi,

Supposing I have two cars A and B. A always arrives at every 10 minutes while B arrives at every 5 minutes or less after the arrival of A. Sometimes B arrives at a time not equal to 5 minutes, say 12 minutes after the arrival of A. I am looking for a suggestion or a code that will match A to all Bs whose time of arrival was 5 minutes or less. That is if the time difference between A and B in this case is 5, then match A and B and out the output in C. As long as the difference in the time of arrival of A and B is 5 minutes or less (should never go over 5 minutes), then match them and output the result in C.

Thank you so much.