is it ok if I start a working for The Sun 666 right after the day like on sunday at 0:25 AM because now it s saturday and it s venus time and The Sun is best to start on a sunday and I was wondering if it s ok to start right at 0:25 AM when I got the time for The Sun
The time of day, from an astrological perspective, is not based on midnight, but on the sun rise. This was described in this post, which you should read fully: HPZM: Questions About Planetary Squares AnsweredFull site ↗
So if Saturday is on the 1st of May, technically it is still Saturday until 6am of the 2nd of May. Only at that point does it become Sunday. You can also see this on planetary hour websites: https://planetaryhours.net/
Also be mindful of the sign of the Sun when you want to do Squares. This is shown on the calendar. At the time of your post, the Sun had left Aries (its exalted sign) and entered into Taurus. You can still use this in a Square, but this earth sign is not nearly as strong as the Sun in firey Aries.
The next best time to do a solar working (not a Square) would be the Summer Solstice in June. The Sun is in a powerful position here, despite its sign being the water-based Cancer. After this, the Sun will enter Leo in July, and you can do a Square here.