Sorry, but I must disagree here.....
I am an "orb slob" and use wide orbs. With the outer planets, I use three degrees, but the personal planet transits, I'll use seven to ten. A lot depends on the actual chart I'm reading and how many planets are being affects. If a configuration is involved, that deems extra consideration.
I ALWAYS take into account the progressed Moon to see if that's linking with a natal planet and a transit. The progressed Moon itself is usually a three month span (applying, exact, leaving), but I've seen it work longer in some cases.
I'm not suggesting that anyone adopt my method, but it works for me.
AG