PERIOD_BASIS is an optional fixed lexicon field that defines the time period (hour, day, week, year) in which the review period value is expressed.
X_PERIOD_BASIS is a fixed lexicon with the following values:
| Saved Value | Displayed Value |
|---|---|
| 01 | Year(s) |
| 02 | Month(s) |
| 03 | Semi-Monthly |
| 04 | Bi-Weekly |
| 05 | Week(s) |
| 06 | Day(s) |
| 07 | Hour(s) |
| 08 | Unit(s) |
