Notes

• The due date is 40 weeks after the last menstrual period, or 38 weeks after conception (fertilization).
• On the date of birth, a baby is on the first day of life (day of life 1), but is zero days old.
• Postmenstrual age is the gestational age at birth plus the age in days on the date of interest.
• Dates are interpreted semi-intelligently, but be aware of possible errors if unrecognized formats are used.
• Entries that contradict each other are reported, and nothing is filled in until they agree.

Based on

• Fierson WM, AAP Section on Ophthalmology. Pediatrics 2018;142:e20183061