Use this site to keep track of the number of days since significant dates like birth dates or a sobriety dates, anniversaries etc.

No. This website uses local storage in your browser to remember your "settings" so there is no need to login. See the FAQ entry on browser storage for more information.

You can create an account for free, with a name and valid email and you can use the local storage feature to use the site without a login. However, you may want an login if:

1) You have multiple devices and would like the same data on each. (of course you could always just enter the data on each device/browser).
2) You want to be able to reorder and edit the entries. The browser version only allows you to add to the end and delete.
3) You want to set up notifications so you can be notified by email of upcoming counter milestones.

No problem, just add your counters on the settings page and you'll be able to see them when you visit the home page. Just remember that you will have a different set of counters on each device.

The easiest way to keep everything in sync is to always login, when you add a counter. Use the reorder page to get them in the sequence you want, and then visit each browser/device and export replacing the browser content.

Browser or more specifically local storage is stored with your browser (chrome, firefox, IE, etc.). The advantage is that you do not have to login or have an account to use it. When you visit the site, if you have set up counters on the settings page, the counter data will be presented on the home page without even having to login.

The downside is that you have a different version on chrome than you do on firefox, or your phone. Also, not all browser versions support local storage, so you may have to create a login anyway to use the site. Also, local storage may be deleted if you clear your cache, so it is highly recommended that you keep your data backed up somewhere else.

If you create an account, counters you create are stored on the server in "cloud storage". The advantage here is that you can share your data between multiple browsers and your phone or pad. The disadvantage is that you have to login to access the data.

However, you can use the sync function to synchronize the browser and cloud storage, and get the best of both worlds. You won't have to login each time you visit the site, but you can easily share data between various browsers and devices. See the entry on syncing for more information.

The Sync page allows you to synchronize entries between browser and cloud storage. You can import entries from browser storage to cloud storage, export cloud entries to the browser or both.

When exporting you can choose to overwrite browser storage so you are sure that it is an exact duplicate of what is in the cloud. (this avoids leaving any extraneous entries in browser storage). You will also want to choose the override option of you want to make sure the sequence matches.