Some things need to happen at a specific time, not just "at some point during the shift" — a scheduled reminder makes sure they're not forgotten.
Create a reminder with a specific time (or a recurring schedule) and a message describing what needs to happen. Target it at specific departments, so only the people it's actually relevant to see it.
When the scheduled time arrives, the reminder appears as a popup for everyone in the targeted department who's logged in. It stays visible until dismissed, and dismissing it is a deliberate action — it won't silently disappear before someone's actually seen it.