Surely this type of split has happened in the past?
It seems not only is their software written in COBOL, they also hard-code things like stock names, and split ratios, and need to recompile multiple programs.
Or perhaps they are getting work experience preschoolers to write the software....?
Yes it is no big deal, and it will all be sorted.
The software industry is full of problems created by dumb design decisions, but they did have a few weeks notice, and on the surface this doesn't seem like an overly difficult problem.. So even by software industry standards, this is a shambles...