He has until Saturday the 19th to act, one way or another.
If he fails to fulfil his duties under the Act, court proceedings will begin on Monday the 21st. Justice can move very swiftly when required, so I would expect some sort of remedy in place by Friday the 25th at the latest.
Parliament is due to sit throughout, so outside of the judiciary there is still the possibility of further legislative measures.
The Inner House of the Court of Session is booked for a hearing on Monday. If he fails to comply with undertakings given to the court, I'd be positive they'd issue a remedy on Monday or Tuesday by the latest.