For the free members you can modify an entry - including changing the photo, title, date and description - for up to 5 days after is has been published.
To do this, go on to the entry and click on the 'More Info' button beneath the tags section.
Click the pencil icon button that appears and follow the instructions.
After the 5 day cut-off, you can only modify the entry's tag and location.
A premium benefit of paid membership journal owners can go back and make changes on their entries at anytime.