This morning a customer asked me to round a DateTime value to the nearest quarter hour. I had written this logic for them before but we couldn’t find the formula so I started from scratch. When I was done it didn’t look familiar so I suspected I had used a different approach this time.

Later we found the original formula, and it was longer and more complex. That is when I remembered writing it, and saying at the time that there had to be a more elegant approach. I must have been off that day because I couldn’t seem to find the simple solution and just wrote something that worked.  Today it clicked:

Local DateTimeVar DT := {Orders.Ship Date};
Local DateVar D := Date(DT);
Local numbervar Sec := DateDiff('s', D, DT);
DateAdd('s', Mround(Sec, 15*60), D);

And thanks to Ido Millet of Millet Software for suggesting the even better approach to this formula now shown above.