How can I restart a chronological reading plan?

Welcome Tom! [:)]

How do I restart the plan?

1. Open the reading plan document.
2. Edit the document and change the starting date to today (or some other time in the future). 
3. Click "done." 

The reading plan will reset. 

That did not remove the completed checkmarks.

Can you provide screenshots? That will help me see what you are seeing. 

Before I edit. Note that all entries are checked off as completed. This means that the prompts it displayed to navigate the reading passages no longer appear in the text.

After editing to restart in 2 days

After hitting Done. Note the completion checkmarks are still there and the internal prompts are still gone.

I don't know what to tell you. When I do so, it always resets. 

• Did you verify that the date is for this calendar year? 
• Did you try making the plan start today? 
• Have you tried right clicking on the first reading date and choosing various options?

I don't think this is a difference between windows and Mac, but I am on Mac. 

• Did you verify that the date is for this calendar year?  Yes
• Did you try making the plan start today? Yes
• Have you tried right clicking on the first reading date and choosing various options? I would have to change every individual entry to unread.

I want to simply restart the reading plan as though I had never done it before, i.e., every day marked unread.

I want to simply restart the reading plan as though I had never done it before, i.e., every day marked unread.

As I mentioned earlier, I am unsure why it did not work for you. Here is what it does for me: 

It looks like you are using a custom reading plan. I am using a predefined reading plan (NT in 3 months). I completed it once and want to repeat it.

It looks like you are using a custom reading plan

I don't know why that would make a difference, and indeed, it doesn't.

EDIT: My screenshot won't post currently.