According to the HM Customs BVI FB page in June 2018, the schedule was:

BVI Customs Ports of Entry for boats:
Road Town Customs, Tortola
Hours: 8:30a.m.-5p.m.
Tel.:1(284)468-5060, 5195, 4927, 4929

West End Ferry Terminal, Tortola
Hours: 8:30a.m.-5:00p.m.
Tel.:1(284)468-4061, 4067, 4063

Building adjacent to Virgin Gorda Yacht Harbor Marina, Spanish Town, Virgin Gorda
Hours: 8:30a.m.–4:30p.m.
Tel.:1(284)468-6553, 6552, 6551, 6614, 6549

Gun Creek, Virgin Gorda (Currently Closed)
Hours: 8:30a.m.–4:30p.m. Tel.:1(284)468-6601

Great Harbour, Jost Van Dyke
Hours: 8:30a.m.–4:30p.m.
Tel.:1(284)494-3450, 1(284)468-6853