Can I write a recursive depth JavaScript parser in 1.5 days? The answer is yes, but it doesn't support the complete language yet. So far I don't support:

-anonymous functions
-the "with" statement
-"for...in" blocks
-labels and labeled continues (bet you didn't know JavaScript had labels!)
-any of the bitwise operators ( & | ^ << >>)
-assignment with operations ( += /= -= etc)
-the ?: construct
-array or object literals
-declaring and initializing multiple variables with a single var statement.

To be fair, I've just been writing the JS parser. I am using a JS tokenizer I wrote a few months back (though I've been finding/fixing a number of bugs in it today).