Thanks for journeying with me, fellow menstruator! This journal is 31 days long. You may choose to start it at the beginning of the month, on the first day of your bleed, or on the new moon. While the moon cycle is 28 days long and a month is ~30/31 days, any given menstrual cycle could be longer or shorter. This is especially dependent upon where you are in your journey and many internal/external factors. This is why I have left the start date up to the journaler. You may or may not use each day in the journal. I encourage you to use this as a tool to get to know yourself better- charting what stand out most to you and not putting too much pressure on yourself in the process.
Happy charting!