User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:20.0) Gecko/20100101 Firefox/20.0 Build ID: 20130409194949 Steps to reproduce: test case: js> Date.parse("Sat Jan 01 107374182499 00:00:00 GMT+0000") 915148800000 Maybe it's better to return NaN instead of 915148800000, but possibly you just close as WONTFIX, since the behaviour is implementation defined in this case. (JSC/V8/IE10/Opera do return NaN.)

Waldo, what do you think we should do here?

Given we're looking at signed integer overflow in the implementation here, which in C++ has undefined behavior, we certainly need to fix *something* here. The exact behavior for the input string is, as comment 0 implies, not all that important, I'd agree.