I know of many desks still using excel to run/update models which are almost always consumed by human traders.
This is a very antiquated and generally fragile system that has a very steep learning curve with very expensive maintenance in the form of what are often called "Junior Portfolio Manager" or "Analyst" being mostly responsible for waking up before the rest of the team to log in, make sure the spreadsheets were/are updating, and fix any issues.
The "scheduling" for these systems is usually a manual start or in more sophisticated teams, a scheduled job on a windows desktop (which fails ~30% of the time for unknown reasons)
I personally know several people that started this way, survived for 3-5 years and then moved to larger/more successful teams or companies that had the resources and knowledge to actually solve these problems.
Anyone thinking about going this route would be better served by picking up some basic Python.