You are sharing a web layer with data that has Editor Tracking enabled and set to record dates in database time. Although all services can include data where Editor Tracking is enabled and set to record dates in Coordinated Universal Time (UTC) only ArcGIS Online and Portal for ArcGIS 10.4 and later support Editor Tracking with dates recorded in database time. This includes layers of standalone tables that reference datasets with Editor Tracking enabled.
The <value> parameter indicates if layers, tables or both record Editor Tracking dates in database time.
Editor Tracking records who created or updated features and when changes occurred. Editor Tracking is required if you want to apply rules controlling edit permissions in feature services with ownership based on access control.
If you plan to edit with the feature service, use UTC, a standard that is unaffected by differences in time zones. Since editors can apply edits from potentially anywhere in the world, UTC works well. UTC is also recommended if you plan to do replication across time zones.