The year range differs between the source item and target item or form

The year range for a target date time item and how it appears on a target form depend on the following criteria:

If the inherit option under Year range in Control Styles is checked and the source date time item doesn't have a specific year range on its design, the target item uses the year range from study style.
If the inherit option under Year range in Control Styles is checked and the source date time item has a specific year range on its design, the target item uses the year range specified by the source item's design.
On the item layout, if the inherit option under Year range in Control Styles is unchecked (overridden) and the user specifies a different year range, this year range is used as default when creating a new form layout. Existing form layouts with the item are not affected.
On the form layout, if the inherit option under Year range in Control Styles is unchecked (overridden) and the user specifies a different year range, this year range is used as the year range for the item on that form.

To confirm the effective year range for the item, use the Preview Annotated Form in the form layout editor.