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Proposed Release Schedule for New Problems

  • Problem 718 is scheduled for Saturday, 30th May 2020, 05:00 pm
  • Problem 719 is scheduled for Saturday, 6th June 2020, 08:00 pm
  • Problem 720 is scheduled for Saturday, 13th June 2020, 11:00 pm
  • Problem 721 is scheduled for Sunday, 21st June 2020, 02:00 am
  • Problem 722 is scheduled for Sunday, 28th June 2020, 05:00 am
  • Problem 723 is scheduled for Sunday, 5th July 2020, 08:00 am

Recent News

25 April 2020: Saving Draft Posts

Many of us have experienced the frustration of taking the time to write that perfect post and, for whatever reason, the post was lost before it was published.

In an attempt to address this potential issue, a new feature has been added to projecteuler.net. Whilst you are composing or editing a post in one of the problem threads, a draft of your post will be saved in your own browser's local storage. In theory, this would allow your post to be recovered in the event of an unexpected page error or accidentally navigating away from the page. If you cancel or successfully publish your post, then the data for that post will be deleted from local storage. It should also be noted that when you sign-out, all of the contents of your local storage for Project Euler will be cleared. Our privacy policy has been updated to include this information.

We hope that you find this feature useful.

8 April 2020: One Million Members

On Sunday 5 April 2020 the Project Euler membership first exceeded one million members. From humble beginnings, back in 2001, we could never have anticipated how it would have grown to what it has become today. That has only happened because of you, our members, and the team who have worked tirelessly throughout the years to bring high quality problems, week after week.

So this Saturday we will be releasing two problems, one of which will be to celebrate that milestone. Thank you to everyone for being a part of Project Euler and we hope that you continue to enjoy solving the problems for many years to come.

28 March 2020: Daylight Saving Time

In contrast to previous years, the Project Euler release schedule will not observe the UK daylight saving time that is due to come in effect on Sunday 29th March 2020. From problem 709 onwards, release times will follow a pattern based on UTC. We hope this gives a more consistent experience for our international community.

14 October 2019: Maintenance Notice

On Tuesday evening 15 October 2019 (UK time), Project Euler will be inaccessible for maintenance due to an internal migration to a new VPS. Although we have been happy with the general performance on the current server, by moving to a more powerful server we are hoping that this will provide a stable environment for quite some time to come.

After the DB migration and testing has been completed it will be necessary to update the DNS on the VPS cluster. For most people this should happen quickly, but fully propagating throughout the global network means that some members may have to wait longer. Whilst your local DNS has not been updated you will continue to point at the old server, which will remain in maintenance status. So as soon as Project Euler appears to be back online you will know that your DNS has been updated; you will be on the new server and able to continue solving problems. Due to the way we are handling this there should be no data loss.

Whilst the main website is inaccessible we would remind you that a static version of the problems can be found at https://projecteuler.info. The problem set is up-to-date and although it will not update your profile, you are able to check answers. This link will appear on the maintenance notice page when it appears.

We hope that the move goes smoothly, but we would ask for your patience and understanding if we encounter any issues.

25 August 2019: DB Migration Issue

To keep the website running optimally it becomes necessary for our hosts to periodically migrate the DB to a new server. We are very grateful for their diligence in this matter and it has always happened in the past without incident. However, today it seems that some of the data on the new server became corrupt during the transfer. Consequently it was impossible to sign-in, giving the impression that your account no longer existed. Fortunately, all the data remained intact on the old server.

So once the issue had been reported our hosts were able to point the site back to the DB on the old server before carefully ensuring that all of the data was migrated properly this time.

We are very sorry for the inconvenience and the scare this might have caused some members when they thought for a moment that their accounts had disappeared.

The site is now pointing at the DB on the new server and it should all be working as expected. It is highly unlikely that any data has been lost during the migration, but if you solved any problems in the last day, then for your own peace of mind it is recommended that you check no progress has been lost.