I don't think there is any such "time" restriction except for...

I don't think there is any such "time" restriction except for that imosed by SEN's own procedure.

The restrictions, in principle, relate more to knowledge than time.
If an employee /director is in possession of price sensitive knowledge ( that is not known to the market) then that person cannot trade in the company's shares for risk of insider trading.

It is impractical to have an externally imposed restriction such as "X days prior" given that a director may in all innocence buy shares today only to see that a major price sensitive event occurs in two weeks time and through no fault of his own the director/employee has contravened the legislation.

Having "X days after" is totally unnecessary because the market is fully informed anyway.