The one in Morristown is planned for the 4th (Saturday), from 11am to 1pm, on The Green in Morristown. Their website is here: http://themorristownteaparty.org/
The one in Summit is planned for the **3rd** (Friday), from 3PM to 6PM, on The Village Green across from the train station. Their website is here: http://njcitizensforliberty.com/
To check for other Independence Day Tea Parties in New Jersey, go to this website:
and select "NJ" from the state list.