simplest thing is to just calculate the days using curtime - boottime / 86400.
The modification for this is less obtrusive anyway.
Suggested by: Bill Fenner <fenner@parc.xerox.com>
that if you do an rup on a machine that's been running longer than a year,
you get the wrong day count. Now we factor in 365 * (curtime.tm_year -
boottime.tm_year) to get the correct value. (I noticed this while running
rup on a SunOS machine I have that's been up 525 days. My FreeBSD
machines all said it had only been up for 160 (525-365) days. :)