If you have cookies enabled the system will remember you.
Do you know if your browser is set to delete cookies when closing?
If you are using firefox, make sure your cookie preference is set to "keep until they expire".
See this page for more info:https://support.mozilla.org/en-US/kb/enable-and-disable-cookies-website-preferences
If you are using Chrome:
make sure your cookie settings are set to "Allow local data to be set (recommended)" like in this picture
If you are using Internet Explorer or Safari
explore your browser settings and verify your browser:
1) can accept cookies from stretchclock.com
2) does not delete the cookies until they expire.
If you set your browser settings to these settings you will not have to log in for each break.
if you need more assistance.
Please contact support and let us know what browser you are using