I used Safeguard for the first foal worming at 4 weeks (if memory serves me right) and Ivermectin monthly there after until I year old. Then use a regular schedule of every 8 weeks as for an adult mini. Rabbitsfizz can give you a schedule that is very good. I use it. What is important is targeting the parasites at the right time of year (for where you live, it can vary) with the correct drug ie. wormer.
Let me repeat, target the type of parasites at the correct time of year for you, with the correct drug. Safeguard is not effective on most of the parasites horses pick up.
Let me edit, you can do a search and a thousand threads will come up. Read what you want but Rabbits schedule is the best and most effective at the right times in my opinion. I am getting ready to double dose for five days with Safeguard in a couple of weeks for this area. And my vet told me to avoid Zimecterin Gold about 8 years ago for our Quarter Horses so we use Equimax and also avoid Quest.