# Use the following time scale for exposure time

Choose the time scale for exposure.

Common time scales include:

Time Scale | Expressed in Days
Weeks | 7
Months | 30.4375
Years | 365.25

Exposure calculations differ depending on whether each subject experienced the event:

Does the subject experience the event? | Start | End
No | reference start date (RFSTDTC) | reference end date (RFENDTC)
Yes | reference start date (RFSTDTC) | the earliest event start date (AESTDTC)

To Select the Time Scale for Exposure:

| 8 | Specify Log Linear for Fit model type.

| 8 | Click the radio button corresponding to your choice.