How often the value occurs. For example, if this value is 2 the event will occur on every other unit of time.

The offset of the frequency which is between 0 and less than every. This is 0 by default which means the frequency starts on 0 and occurs on every, every * 2, every * 3, etc. For example if this value is 1 and every is 3 the sequence will be: 1, 4, 7, 11, ...