There is no specific time to buy bitcoin because this goes back to your purchase target at what price, for example if you buy at a falling price then a week later it drops again you can buy again, right? Or use the DCA strategy to get a better average price.

Are you investing in bitcoin long term?
Buy when it is a bearish phase because at that time bitcoin is experiencing a long decline, then you can sell when entering the bullish then this is 1 4-year cycle so you have to be a little patient.