Arnout Engelen pointed out, that you could create a php libical wrapper:

PHP currently seems to lack proper iCalendar libraries.
Since there already is a LibicalWrap.i for the Python
bindings, it's not very hard to make a libical .so that
can be accessed from PHP. Would be a valuable building
block in the practical adoption of the iCalendar
standard (imho).

I'm attaching a Makefile how I whipped together the
.so, and a small example of how to use the resulting
library. Obviously this is not good enough for in the
official distribution, but it'll probably give you an
idea of how to make a PHP binding.

However, it's here for documentation purposes, until s.b. comes around the corner
with the demand and a Patch how to implement it clean. Feeling addressed? Send Diffs!