The timer widget (e.g. result for "30 second timer") should begin counting down immediately after the page loads, rather than requiring the user to press "Start".
This is the current behavior of the equivalent timer widgets on Google, Bing, and DDG. I believe these search engines have made the correct assumption about the user's intention when searching for a timer, namely: if the user has searched for a timer with a specific time, they probably don't intend to introduce any additional delay.