When to know its the first day of vegetative?

Hi there Borneo, great question, but unfortunately it doesnt have a fixed answer. I personally start counting from when it pops out the soil. Others will start counting veg after the seedling is transplanted. Still others, will start counting after the first true leafs are formed. The main thing is you should be consistent, just so you can compare apples with apples and oranges with oranges. In the end , your grow diaries are for you, so you have to do what's right for yourself. Does that make sense? Hope this helps ! 🚀