Update: This was permanently resolved as of 4/2 - reports using specific time-stamps now work as expected.
ServiceNow customers using its reporting features have noticed some of their saved reports appearing blank. The common criteria is when a report uses a specific time-stamp in their filtering criteria. It is not affecting reports that use the pre-defined time-stamps (e.g., 'Yesterday', 'Last Week', 'Last 60 Days').
The workaround, if possible, is to use a pre-defined time-stamp from the drop-down list. We are working to resolve this issue, and apologize for the inconvenience. There is no ETA at this time, but we will be sharing additional information as it becomes available.