Massachusetts time-of-use hours by utility

Across the 4 TOU plans tou.tools tracks in Massachusetts, the most common on-peak window is 8 AM – 9 PM (3 plans); others run 9 AM – 6 PM and 1 PM – 9 PM. Every hour outside the on-peak (and any mid-peak) window is billed as off-peak. Exact boundaries vary by utility and plan — see each utility's schedule above.

tou.tools tracks 2 Massachusetts utilities with at least one active TOU rate plan — 4 active schedules in total. The largest by customers served are NSTAR Electric Company and Massachusetts Electric Co. They span investor-owned utilities. The full list above is sorted by customers served.

It depends on the plan. Of the 4 TOU plans we track in Massachusetts, 1 apply on-peak periods every day including weekends, while 3 restrict on-peak to weekdays and treat weekends as off-peak. Many tariffs also treat observed holidays as off-peak; the Days column in each schedule above shows the exact rule.

Some do. Of the 4 TOU plans we track in Massachusetts, 2 shift their period boundaries between seasons (typically summer and winter), while 2 keep the same hours year-round. Each schedule above lists its exact season dates.

tou.tools tracks 1 EV-specific rate plan in Massachusetts (OPCR). On EV time-of-use plans the lowest-cost window is generally the overnight super-off-peak or off-peak period; charging then avoids the on-peak window. See the EV plan schedules for the exact hours.

tou.tools maps 532 Massachusetts ZIP codes to the utilities that serve them. Because service territories can overlap, a ZIP may return more than one candidate utility; supplying a full street address resolves it to a single utility via a geocoded point-in-territory lookup. The REST API and MCP server both return the matching utility and its current TOU period.