Pro-C ManualHere's your manual.
Odd and Even days are exactly what they sound like. April 2nd = even day. April 1st = odd day.
The date determines odd and even.
This is a good way to water if you want to water every other day. Of course at the end of the month you may have two days in a row water.
If you want to run on specific days of the week then ignore the odd and even days. Just program each individual day you want to water.