I've got a logfile in the standard syslog format. It looks like this, except with hundreds of lines per second:

Jan 11 07:48:46 blahblahblah...
Jan 11 07:49:00 blahblahblah...
Jan 11 07:50:13 blahblahblah...
Jan 11 07:51:22 blahblahblah...
Jan 11 07:58:04 blahblahblah...

It doesn't roll at exactly midnight, but it'll never have more than two days in it.

I often have to extract a timeslice from this file. I'd like to write a general-purpose script for this, that I can call like:

$ timegrep 22:30-02:00 /logs/something.log

...and have it pull out the lines from 22:30, onward across the midnight boundary, until 2am the next day.

There are a few caveats:

• I don't want to have to bother typing the date(s) on the command line, just the times. The program should be smart enough to figure them out.
• The log date format doesn't include the year, so it should guess based on the current year, but nonetheless do the right thing around New Year's Day.
• I want it to be fast -- it should use the fact that the lines are in order to seek around in the file and use a binary search.

Before I spend a bunch of time writing this, does it already exist?