Forum Discussion
Highlight rows with overlapping dates
You can follow this article to create a modern calendar view: Create a modern Calendar view in SharePoint Online/Microsoft Lists
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JenniferPigeon Unfortunately, there is no SharePoint online modern experience out of the box options available for your requirements to highlight the rows with overlapping dates.
Both SharePoint calculated columns and JSON formatting cannot read the column values from another rows/items in the list.
You will have to use the custom solution for your requirements, probably SPFx field customizer to just highlight the date column cell or SPFx web part to develop complete new solution for list view (table structure) and color formatting OR use Power Apps to create canvas application and use it instead of default SharePoint list views.
Please click Mark as Best Response & Like if my post helped you to solve your issue. This will help others to find the correct solution easily. It also closes the item. If the post was useful in other ways, please consider giving it Like.