An action is taken seasonably when it is taken at or within the time agreed or if no time is agreed at or within a reasonable time.
having very long suspended our conference about the freshly mention'd Subject, it was so newly begun when you came in, that we shall scarce need to repeat any thing to acquaint you With what has pass'd betwixt us before your arrival, so that I cannot but look upon it as a fortunate Accident that you should come so seasonably, to be not hearers alone, but we hope Interlocutors at our conference.
It was a wild, cold, seasonable night of March, with a pale moon, lying on her back as though the wind had tilted her, and flying wrack of the most diaphanous and lawny texture.
Thomas Salusbury (1662): Nor is it seasonable to have to do with Hercules, whil'st he is enraged, and amongst the Furies.