Expiration Date exception when trying to load pass on device or simulator

[tenneyb]

Unable to parse expirationDate /Date(1487415600000-0000)/ as a date. We expect dates in "W3C date time stamp format", either "Complete date plus hours and minutes" or "Complete date plus hours, minutes and seconds". For example, 1980-05-07T10:30-05:00.

using C# DateTime on the Pass.expirationDate field, if I leave this field out (which I really can't) the pass works fine Help :) ?!