Criterion for the length of the booking in days.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/common/criteria.proto)

| Fields ||
|---|---|
| ## `max_days` | `int64` High end of the number of days in the booking. |
| ## `min_days` | `int64` Low end of the number of days in the booking. |