There is an intentional 3-month max date range for this tool, given it can make hundreds of API queries. I'm not sure if this restriction actually helps with performance, maybe others could shed light on this? E.g. We're making the same number of queries either way, so does it matter how wide the range is?

To get the most recent data, omit the start and end parameters from the URL and instead use "range=latest-N" where N is the number of days. E.g. This shows the latest 90 days of data: https://tools.wmflabs.org/langviews/?project=en.wikipedia.org&platform=all-access&agent=user&range=latest-90&page=Heterosis&sort=views&direction=1&view=list

See the URL documentation for more info: https://tools.wmflabs.org/langviews/url_structure/