How to Use the Baby Milestone Countdown
From the one-month mark to the 100-day celebration to the first birthday, a baby's first year is full of milestones worth planning for. This calculator takes a single birth date and instantly works out the exact date and countdown for all three: one month (day 30), the 100-day milestone, and the first birthday.
The 100-day milestone counts the birth date as day 1, so it lands 99 days after birth - a celebration that's grown popular even outside its East Asian origins, alongside the more familiar one-month and first-birthday markers. The first birthday is calculated as exactly one year after the birth date, with full leap-year accuracy.
Since these milestones often involve booking a venue, scheduling photos, or sending invitations, seeing all three countdowns at once makes it easier to plan ahead with plenty of lead time.
Frequently Asked Questions
The birth date counts as day 1, so the 100-day milestone falls 99 days after the birth date.
Yes, the first birthday falls exactly one year after the birth date, and this calculator accounts for leap years so the date is always exact.