[kronolith] strange error

[Craig White]

kronolith-1.1.3

horde-2.2.7.tar.gz
imp-3.2.7.tar.gz
mnemo-1.1.3.tar.gz
nag-1.1.2.tar.gz
turba-1.2.4.tar.gz

All seem fine except for kronolith. When I go to kronolith window, I get
the following error on screen...

Warning: main(Date/Calc.php): failed to open stream: No such file or
directory in /var/www/html/horde/kronolith/lib/base.php on line 63

Fatal error: main(): Failed opening required
'Date/Calc.php' (include_path='.:/php/includes:/usr/share/php:/usr/bin/pear:/usr/share/pear') in /var/www/html/horde/kronolith/lib/base.php on line 63

sql table is created. pear is in /usr/bin/pear

Whiteboxlinux php-4.3.2-19.ent

I have installed pear / Log, Mail_Mime and have run pear upgrade

Any clues?

Craig