Quote from the official documentation
Timestamps are accepted in the form of millisecond timestamps (as returned by Date.getTime() or as strings in the following formats:
2012 2012 Q1 2012 W1 2012-02 2012-02-24 2012-02-24 15:00 2012-02-24 15:00:00 2012-02-24 15:00:00.000
Note: when using millisecond timestamps, it's recommended that you check out the dateFormat option. Note 2: date/time strings can optionally contain a T between the date and time parts, and/or a Z suffix, for compatibility with ISO-8601 dates.
Just replace slashes by hyphens, and it should be ok