This analogy seems helpful.
From this article: Range ambiguity resolution
the apparent range is a modulo function of true range.
Time-keeping on this clock uses arithmetic modulo 12
A familiar use of modular arithmetic is in the 12-hour clock, in which the day is divided into two 12-hour periods. If the time is 7:00 now, then 8 hours later it will be 3:00. Usual addition would suggest that the later time should be 7 + 8 = 15, but this is not the answer because clock time “wraps around” every 12 hours.