no due date

When scheduling a todo with Sandy, it appears that if she doesn't see a due date in the message, she will pick a default due date of today. Since I don't always want to schedule a todo on a specific day, I'll have to go on the web site, and take out the due date for those items. I didn't see anything in the guide or forums describing how to add a todo and have no due date included, but would love to have that ability. I could always call the unscheduled todo's something else and have the Daily Digest customized to show them, but just wanted to see if there was another way to do this when sending Sandy a todo.