The date can be adjusted to anytime past, present, or future in Day One. This allows you to retroactively create past entries from memory or using photos.
While editing an entry, tap the date at the top. Use the Calendar to change the date or use the options below the calendar to set the date/time. There is an option to set an entry to "All-day"
Or tap the map at the bottom to open the Entry Info/Metadata view. Then tap the Date field to edit.
Using photos to set the date and location of the entry is also an option in the Metadata view.
There are several options to change the date.
Click the date at the top of the entry. Entries can now be set to "All-day".
2. Click the Paper Clip icon at the bottom right of an entry and then choose Date
3. Click the More (•••) icon at the top right and choose Date