Don't get too hung up on specific numbers of hours, it can vary depending on your needs for the day and by individual. just go from dinner to late morning/noon without any food coming in. You can still eat 3 meals in the remaining time, skipping breakfast doesn't mean you can never eat during that time of day.
It is important all cycle long and for at least 6 weeks before.
Estrogen dominance is not a medically recognized condition and while I'm not saying it's made up, it's not something that I feel is proven. We do try to lower estrogen overall for a pink sway with the LE Diet, weight loss, and fiber so it's all good either way.