Revert "add cal.erl"

This reverts commit 171c87226777f875698de5ca066ef691f88be9cf.

Conflicts:

	cal.erl
Revert "Update cal.erl"

This reverts commit 494fac7adafe22d9a9a458de954bd304d9854fbc.

Conflicts:

	cal.erl
handle conflicts and add the export sub function