I too have long ago discovered that my best way to ensure I get to something needing to be done is to put it on a calendar with the deadline. I might have to push things back, but I have to think about it, and I’m regularly reminded until I get the thing done. “Timeful.com” mentioned in the article appears defunct. But, I would recommend the TickTick app (www.ticktick.com) which allows you to categorize your to-do’s, shopping or other lists, as well as fill them in on its integrated calendar and keep it all synchronized together as well as on your handheld and your desktop. You can toggle your view from list to calendar to category as needed with simple clicks. For example, I keep a Christmas list of people I obtain gifts for, etc., and a separate list for household things I need to shop for and buy, separate from my regular weekly groceries for the obvious reason of simplicity and uncluttered management of my purchasing. I plot projects and goals on my calendar with sub-steps listed and targeted out. Deadlines and reminders can be set and moved. Many other features make TickTick app my favorite of all calendar/to-do systems I’ve ever encountered. Free version as well as a paid version with added features; the latter is very well worth it.