Well, I have the following meta tag on index.htm:
<meta http-equiv="content-type" content="text/html; charset=utf-8">
Furthermore, it works fine on my browsers so it could be a local issue. Can you try another browser?
For scheduling instructions, please consult the manual here: https://opensprinkler.freshdesk.com/support/solutions/articles/5000606704-user-manual-firmware-2-1-3-current-