General Information

Negative values take precedence over positive values when determining whether a mission is scheduled on a certain date. If a negative value (for example, format –n, –Dn, –Ln, –DnPi, or –LnPi) in either the DAYS or WDAYS field prevents a mission from being scheduled on a date, the mission will not be scheduled on that date even if a positive value (for example, Ln) would otherwise result in the mission being scheduled on that date.

A maximum of eight periodic values (for example, of types DnPi, –DnPi, LnPi, and –LnPi) can be designated in any desired order.

If periodic and non-periodic values are mixed when specifying parameter WDAYS, processing will depend on the calendar type specified in parameter WCAL.

• If a non-periodic calendar is specified in the WCAL parameter, only non-periodic values in the WDAYS parameter are processed. Periodic values are ignored. In this case, negative periodic values (for example, –DnPi, –LnPi) are also ignored and do not supersede other values.
• If a periodic calendar is specified in the WCAL parameter, all periodic values and the negative non-periodic value -n in the WDAYS parameter are processed; all nonnegative non-periodic values are ignored.

The MONTHS parameter is ignored when periodic values are specified in the WDAYS or DAYS parameter.

The WDAYS parameter cannot be used with the PDS, MINIMUM, and DATES parameters.

When Ln and/or Dn values are specified in a week that overlaps two months, the MONTHS value of the earlier month determines whether Dn or Ln values are applied in the week:

• If the first day of the week falls in a month with a MONTHS value of Y, all Dn and Ln values in that week are applied, even those falling in the next or previous month, when that month has a MONTHS value of N.
• If the first day of the week falls in a month with a MONTHS value of N, no Dn or Ln values in that week are applied (not even if those falling in the next or previous month, when that month has a MONTHS value of Y).