The Calendar (play)

The Calendar is a 1929 play by the British writer Edgar Wallace. It is a crime thriller set in the world of horse racing world, the sport being among Wallace's interests. The protagonist is a financially struggling racehorse owner with a shady reputation. It premiered at the Palace Theatre in Manchester before transferring to Wyndham's Theatre in the West End. 
It was revived for a 42 performance run at the Lyceum Theatre the following year. That year Wallace also adapted it into a novel "of the same title".
Film adaptations.
The tale was adapted for a 1931 film of the same title starring Edna Best and Herbert Marshall. A remake under the same name was released in 1948 with Greta Gynt and John McCallum in the lead roles. Both versions were productions of Gainsborough Pictures.