You can check Rebol http://www.rebol.com/ and the new Red http://www.red-lang.org/ programming languages. The latter one not yet production ready.

In Rebol (and Red) you can just do the following: print 3:30am + 00:07:19 ; increment time values properly

Note that ';' is the identifier for a comment.

Have a look at these:

- https://gist.github.com/akatzbreaker/5849024

- https://github.com/chesles/naturaltime

- https://github.com/kvh/recurrent

- https://github.com/bear/parsedatetime

- https://github.com/Carbon/Language

Python's parsedatetime module can do some level of language parsing.

https://github.com/bear/parsedatetime

Examples:

next thursday at 4pm

at 4pm

2 hours before noon

2 days from tomorrow