Chair, I would just say that motions with dates for ministers' appearances are fairly routine and I wouldn't describe them as overly prescriptive.
I'll just be blunt. I would say “by next Friday”. That gives the ministers, in the middle of a pandemic where people are dying every day and we don't have vaccines, two weeks to come before the Standing Committee on Health. If we get the sense as committee members that is not going to be the case, that they won't be able to fulfill that basic parliamentary function, then I suspect there will probably be some ramifications from the opposition on that.
I would encourage you in your role of chair to perhaps communicate that to the ministers in terms of their understanding of what the gravity of this invitation would be, should it pass.