A system has the following configuration and is monitored by taking jfrs.
OS: Red Hat Enterprise 5
Java: 7u91

The application runs from 4 to 6 hours and jfr is monitoring the application the entire time with these settings:
-XX:FlightRecorderOptions=defaultrecording=true,disk=true,maxage=48h,maxsize=300m

Yet, the recordings still are only 1 hour long.
1) jvm_flightRecording-1jfr
interval is 5 hr 35 min
recording is 1 hr
size is 6,250k

2) jvm_flightRecording-2.jfr
interval is 5 hr 23 min
recording is 1 hr 6 min
size is 4,490k

3) jvm_flightRecording-3.jfr
interval is 6 hr 24 min
recording is 1 hr 6 min
size is 5.056k