How long for Buctril M and Horizon in a tank

Hi,

I have finished spraying and still have 300 gallons of Horizon and Buctril M at full rate in my sprayer tank.

How long will the spray stay viable?

I was thinking of leaving it in the sprayer for a week or two and then go hit some of the heavier thistle patches after a rain (hopefully).

If necessary, I could agitate the tank once a day or so if that's a concern.

Thanks

How long for Buctril M and Horizon in a tank