Why a traditional day may begin at sunrise
A sunrise-based, or savana, day runs from one sunrise to the next, while the familiar calendar date changes at midnight.
STEP 1
Choose the starting point
In this traditional count, sunrise starts a new day and the following sunrise ends it. This is a way to set a day's boundary. It does not change the date shown on your phone or other civil calendar.
STEP 2
Compare it with midnight
A midnight-to-midnight date and a sunrise-to-sunrise interval overlap without matching. The early hours after midnight can still fall inside the interval that began at the previous morning's sunrise.
STEP 3
Work a hypothetical example
Suppose sunrise is 6:00 AM Tuesday and 6:00 AM Wednesday. At 3:00 AM Wednesday, the civil date is Wednesday, but the sunrise-based interval that began Tuesday is still running. Exactly at Wednesday's 6:00 AM sunrise, the next interval starts. These times are illustrative; real sunrise varies with the date and location.
STEP 4
Check the calendar's location
Before interpreting an entry, read how that calendar defines its day and which location its sunrise time refers to. Also check the time zone. Keep the printed civil date, sunrise boundary and event time separate when comparing entries.