All configurations are in 24 format (Schedule maintaince, business hours etc) and all views (chart widgets for example) are in 12 hour format now. The
We are yet to support international format (yyyy-mm-dd) however, we'll take this a request a track it internally.
As for timezone, we take the timezone from MyAccount settings "Timezone for reports" as the standard for all reports and alert mails.
Product Manager, Site24x7