Is there a Solaris utility which reports the minimum free space on a file system over the preceding 168 hours (one week)? The concern with using a nightly df is that there might be intraday jobs which nearly exhaust disk space when they run, but clean up after themselves so there's no apparent problem when df runs.
SnapOverflow
I don't believe there is any built-in system that does this, but nearly every monitoring system I've ever used is capable of trending disk space over time (at whatever granularity your polling cycle is, over varying & configurable lengths of time).
If you do not have a monitoring system in place I would suggest checking out Cacti (if you just need trending) or InterMapper if you need alerting + trending. Something could probably be worked out using Nagios or any number of other solutions as well...
Short answer: no.
You could define a smaller interval between df runs as to catch this relatively fast running scripts. How fast a script will be able to fill up your filesystems depend on their size but it should give you an approximation for the worst case based on your disk speed.