From 97cfd40649abab832315f00e6a07e5b6b9a17e23 Mon Sep 17 00:00:00 2001
From: Tyler Trahan <tyler@tylertrahan.com>
Date: Wed, 12 Apr 2023 14:52:37 -0400
Subject: [PATCH] Fix #10630: Don't allow shifting service date earlier than 0
 (#10643)

---
 src/vehicle.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index bf35856f88..a979d4de3f 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -771,7 +771,7 @@ uint32 Vehicle::GetGRFID() const
  */
 void Vehicle::ShiftDates(int interval)
 {
-	this->date_of_last_service += interval;
+	this->date_of_last_service = std::max(this->date_of_last_service + interval, 0);
 }
 
 /**