If a Tank Chart has been set up and the Water and Fuel depths have been entered, the Fuel gallons will automatically calculate. This can be overridden. For more information about Tank Charts see Tank Setup in Settings.
When everything looks good, click the 'Tank Readings Complete' button. Tank Readings must be complete to complete the Day.
After the complete button is clicked, checkmarks will show up on the button and on the left menu. See images below:
Corrections can always be made before the Day is completed. Please note, anytime changes are made to the grid, the checkmarks will go away and the Complete button needs to be clicked again.