By the use of the oconv function, and your mention of "unix basic", it seems as though your internal time is based on the Pick calandar. Where, day "0" (in "internal" format) on the Pick calendar is December 31, 1967. For example, June 26, 1987 has an internal value of 7117, which is the number of days since 12/31/67.
Is this correct? If so, please let us know, because there may be a module that deals with such a format explicitly.
After doing some minor calculations (e.g. 11982/365 = 32.827 and 11982%365 = 302; 302/30 = 10.0667), I see approximately 32 years and ten month, which from 12/31/67, is 10/20/00. Now, by RFC99 (I think), Perl is going to always be standardized on the UNIX epoch, and everyone here (including myself) is in that mindset. I don't want to go through all of the trouble of trying to find a Pick calandar module until you 100% confirm that this is what your dealing with. Actually, I have already gone to the trouble and haven't found one yet and don't want to continue looking until I've received a confirmation. Of course, you can look too if that is, in fact, what you need. Try here