No founder, organisation or establishing record has been identified for the December 27 observance, and no source gives a reason for the date. The earliest trace is an Internet Archive capture of a third-party holiday listing from August 2022, which dates the listing rather than the day.
Why July 29 became hers
The date is not as ancient as the story. Vatican News puts the start of the liturgical memorial of Saint Martha at the Franciscans, in 1262, who "celebrated her feast on 29 July, eight days after the feast of her sister, St Mary Magdalene."
That placement set Martha inside her sister's octave. The 2021 revision kept the date and changed the title, so a day positioned by reference to Mary Magdalene now names Mary of Bethany and Lazarus beside Martha.
The revision was not only cosmetic. The old Entrance and Communion Antiphons survived unaltered, while the Collect and two other prayers were newly composed.


