Wolfram alpha gets it perfectly right [1], it's not like this is an insurmountable problem. One of the reasons I use this service for simple queries like this. I think siri and other voice assistants use it under the hood as well.
There seem to be a lot of reports that Wolfram|Alpha has gotten "dumber" and this lines up with my experience. But it's still ahead of Google for a lot of queries.
[1] https://www.wolframalpha.com/input?i=last+day+of+march+2022