There is StartTimestamp property used in edit api, which should contain the time, when you started editing the page. This timestamp needs to be in same timezone as wiki is.
How do you get current wiki time, so that you can either calculate the timezone or use the time? For example:
1) Get current wiki time and store it 2) Edit the page 3) Use previously retrieved ts as StartTimestamp
How can I query the mediawiki in order to get the current time from server's point of view