Who's it that says bitcoin has a specific period of purchasing it bitcoin? You should change that awkward thought and get your coins at when you can for bitcoin would always hold the best for you in the nearest future.
Is there someone that says such? because what i see in this market over the years is that we can purchase anytime we wanted and any price we believe it is worth buying .
maybe there are some stupid people that has this attitude in trying to fool someone to believe in their belief but they are very few from us who wanted that all needs to either use crypto or Hold completely.