diff --git a/src/story.cpp b/src/story.cpp
--- a/src/story.cpp
+++ b/src/story.cpp
@@ -345,7 +345,7 @@ CommandCost CmdSetStoryPageTitle(DoComma
  * @param date date
  * @return the cost of this operation or an error
  */
-CommandCost CmdSetStoryPageDate(DoCommandFlag flags, StoryPageID page_id, Date date)
+CommandCost CmdSetStoryPageDate(DoCommandFlag flags, StoryPageID page_id, TimerGameCalendar::Date date)
 {
 	if (_current_company != OWNER_DEITY) return CMD_ERROR;
 	if (!StoryPage::IsValidID(page_id)) return CMD_ERROR;