47 CFR §5.213

1. (a)Unless specified or restricted hours of operation are shown in the station authorization, broadcast experimental radio stations may be operated at any time and are not required to adhere to a regular schedule of operation.
2. (b)The FCC may limit or restrict the periods of station operation in the event interference is caused to other broadcast or non-broadcast stations.
3. (c)The FCC may require that a broadcast experimental radio station conduct such experiments as are deemed desirable and reasonable for development of the type of service for which the station was authorized.