Back when I was a programmer—when Fortran and COBOL were king, and anyone who knew just one assembly language could almost walk on water (I knew 60-bit CPU and 12-bit PPU COMPASS assembler)—there was a distinct difference between the words programme and program.
Program referred to a computer program. An application or function written using a computer programming language, such as Fortran or COBOL.
Whereas a programme was a list of events, or a list of acts or musical items in a show. Or a selection of things to do.
If one saw the words “What is the programme for tonight” then it was clear that one was asking what was going to be happening tonight—what were the planned activities for the evening. If one saw the the words “What is the program for tonight” then the question was probably being asked of a coding team and they were being asked what computer application they would be developing and writing code for that night.
Back then program was not simply a useful abbreviation of programme but a totally different word with a totally different meaning.
Even today the Collins World English Dictionary still makes a distinction between the two words (see image at left).
The 20th Century Chambers Dictionary does not even lower itself to list program as a its own word. They simply point out under programme that it is sometimes abbreviated to program when used in relation to computers.
But sadly writers today do not seem to even realise the word programme even exists.