My First Auto Flower Grow.. When to switch to Flowering?

I am 4 weeks into my first grow. Using a 3x3x6 tent using Advanced Platinum P450 LED Grow light, using FoxFarm organic soil.

I am set up for 18 hours light 6 hours dark. Growing White Diesel Haze Automatic & Skunk #1 Automatic Strains for my first grow.

So far the plants are looking good and they are starting to smell like bud. My LED light system is currently set to Vegetative, but when do I need to set these to flowering?

Whatlight schedule would you recommend for Autos? I understand they will internally start to flower without incorporating a dark period. I was thinking to keep 18 - 20 hours light and 4-6 dark during flowering.

White Diesel Haze Auto Flowering 50 - 65 days
Skunk #1 Auto Flowering 45 - 55 days

What does the amount of days for flowering mean? When I switch to flowering mode on my LED lights I have 15 days until I can harvest?

If there true autos you can leave it at 18/6 or 24 straight and they will flower anyway and they'll appreciate the extra light

At some point you'll want to drop the lights down to 12 or somewhere close to that. They do need to rest in flowering...

At how many weeks should I switch from Veg to Bloom on the LED Light?

What exactly does the below information mean? I am assuming I should put bloom on the White Diesel haze at 50 days..?

White Diesel Haze Auto Flowering 50 - 65 days
Skunk #1 Auto Flowering 45 - 55 days