Trinity Church and Old South Church, two of Boston’s most historic houses of worship, want the city and the state to reconsider a plan to plunk towers atop Back Bay Station.

The reason? Those following Boston development will find it familiar: shadows.

The churches are concerned that the towers, which are due to stretch as high as 365 feet, will cast shadows on their properties during certain times of the year. For instance, per the Globe’s Tim Logan:

At Old South, the impact could be felt most acutely indoors, especially on two huge sets of stained-glass windows on the east- and south-facing walls of the church’s sanctuary. [T]he towers would block sunlight from hitting the windows on mornings in December, the Christmas season, during 9 a.m. and 11 a.m. services.

So far the churches have the support of the Massachusetts Historic Commission, a state body charged with protecting the commonwealth’s historic properties.

The commission says the Back Bay Station towers’ shadows will also affect the Boston Public Library’s McKim Building, the YWCA at Stuart and Clarendon streets, and historic districts in Back Bay and the South End.

For now, the plans for the towers, which developer Boston Properties would build, remain under review.

They are part of a larger 1.26 million-square-foot project that includes an overhaul of the station, so it could come down to whether the powers that be want a brighter, more accessible transit hub, never mind hundreds more apartments in housing-starved Boston, or a more glorious Christmas morning.