If they have a specific timespan in mind, you could just configure the said dashboard for that needed timespan.
Or if you want to keep what it has now and make one specific for their use case, you could clone the current one, adjust the timespan, and provide the link to them.
It all really depends if there is a set timespan they want or if their timespan needs would fluctuate.
You can also now subscribe to dashboards in Cluster version 1.184. This can be done on a weekly/monthly schedule. Read more about it here: https://www.dynatrace.com/news/blog/get-scheduled-reports-on-data-that-matters-to-you-most-by-subscr...