IssueTracker

Please fix this bug. I rely on this calendar software to track my tasks and this is causing me serious trouble.

I'm getting reports from users of an app I developed which uses the Google Tasks API about this issue. Hoping Google will fix this one as it kind of breaks the API functionality..

I see a little bit different issue.  Once the date is "locked out" I cannot see the changes I make with third party apps whether or not I reload one or all of the apps.  Everything displays correctly in the TP Apps on all sync'd devices, but never correctly displayed in the "Google Task" app on any sync'd device.  

If I change the Due Date using the "Google Task" app, everything is displayed correctly in all TP Apps as well as Google Task apps on all sync'd devices.

I have been using Google Tasks with a third-party app for years, to manage personal and professional activities.  This bug is making Tasks much harder to use and trust.  Please prioritize and address.  Thanks.

I use http://calendar.google.com on my desktop and a hhird party app on my mobile devices. I am experiencing the exact behavior described by the original poster. This makes http://calendar.google.com unreliable and not usable. Please fix this bug so that http://calendar.google.com will be usable again.

The OP is absolutely right. After some testing, I'm 99% sure the issue here is that there are two different due date fields in the database: the one available through the Google Tasks API, and the one that Google Calendar (and the rest of GSuite) uses. As the OP and others have said, this started when the due times and task recurrence features were added. Details on how to recreate the problem:

1. Create a Task with a due date (with or without a due time) at https://calendar.google.com/
2. Use any app to update the task's due date via the Google Tasks API, even Google's own: https://developers.google.com/tasks/v1/reference/tasks/update
3. The Google Tasks API will report the date as the one that was changed, but Google Calendar will show the date it originally set

From that point on, changing the date with Google Calendar changes both dates (API and Calendar), but changing via the API only works if the date was never set by Calendar. As soon as Calendar writes to it's other field in the database, it will copy any change it makes to the datetime field the API uses, but will only every use the value it wrote to display in Calendar.

Solving the issue seems fairly straightforward: use the same datetime field in both Google Calendar/GSuite and the Google Tasks API. This would have the added advantage that developers using the Google Tasks API could set due times. Currently the Google Tasks API date is always rounded to 0 UTC, even if you set a time in Calendar, or attempt to set one via the API.

Thanks and have a good one,

Kevin

I have been experiencing exactly the same issue with a little command-line tool I wrote to help manage my task-lists.
Glad to finally find out what the problem is and hoping for a speedy bug-fix from Google.
(This is seriously ruining my productivity at work - I organise everything via Google Tasks!)