diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp
index 1f5f986282..1dc9f22d8f 100644
--- a/src/aircraft_cmd.cpp
+++ b/src/aircraft_cmd.cpp
@@ -22,6 +22,7 @@
 #include "command_func.h"
 #include "window_func.h"
 #include "timer/timer_game_calendar.h"
+#include "timer/timer_game_economy.h"
 #include "vehicle_func.h"
 #include "sound_func.h"
 #include "cheat_type.h"
@@ -338,7 +339,7 @@ CommandCost CmdBuildAircraft(DoCommandFlag flags, TileIndex tile, const Engine *
 
 		v->SetServiceInterval(Company::Get(_current_company)->settings.vehicle.servint_aircraft);
 
-		v->date_of_last_service = TimerGameCalendar::date;
+		v->date_of_last_service = TimerGameEconomy::date;
 		v->date_of_last_service_newgrf = TimerGameCalendar::date;
 		v->build_year = u->build_year = TimerGameCalendar::year;
 
@@ -1555,7 +1556,7 @@ static void AircraftEventHandler_AtTerminal(Aircraft *v, const AirportFTAClass *
 		if (_settings_game.order.serviceathelipad) {
 			if (v->subtype == AIR_HELICOPTER && apc->num_helipads > 0) {
 				/* an excerpt of ServiceAircraft, without the invisibility stuff */
-				v->date_of_last_service = TimerGameCalendar::date;
+				v->date_of_last_service = TimerGameEconomy::date;
 				v->date_of_last_service_newgrf = TimerGameCalendar::date;
 				v->breakdowns_since_last_service = 0;
 				v->reliability = v->GetEngine()->reliability;
diff --git a/src/roadveh_cmd.cpp b/src/roadveh_cmd.cpp
index 80869d9c03..7dfa8863c0 100644
--- a/src/roadveh_cmd.cpp
+++ b/src/roadveh_cmd.cpp
@@ -21,6 +21,7 @@
 #include "strings_func.h"
 #include "tunnelbridge_map.h"
 #include "timer/timer_game_calendar.h"
+#include "timer/timer_game_economy.h"
 #include "vehicle_func.h"
 #include "sound_func.h"
 #include "ai/ai.hpp"
@@ -299,7 +300,7 @@ CommandCost CmdBuildRoadVehicle(DoCommandFlag flags, TileIndex tile, const Engin
 
 		v->SetServiceInterval(Company::Get(v->owner)->settings.vehicle.servint_roadveh);
 
-		v->date_of_last_service = TimerGameCalendar::date;
+		v->date_of_last_service = TimerGameEconomy::date;
 		v->date_of_last_service_newgrf = TimerGameCalendar::date;
 		v->build_year = TimerGameCalendar::year;
 
diff --git a/src/saveload/afterload.cpp b/src/saveload/afterload.cpp
index 3a4467add4..54a73cd193 100644
--- a/src/saveload/afterload.cpp
+++ b/src/saveload/afterload.cpp
@@ -1441,7 +1441,7 @@ bool AfterLoadGame()
 		for (Industry *i : Industry::Iterate())  i->last_prod_year   += EconomyTime::ORIGINAL_BASE_YEAR;
 
 		for (Vehicle *v : Vehicle::Iterate()) {
-			v->date_of_last_service += CalendarTime::DAYS_TILL_ORIGINAL_BASE_YEAR;
+			v->date_of_last_service += EconomyTime::DAYS_TILL_ORIGINAL_BASE_YEAR;
 			v->build_year += CalendarTime::ORIGINAL_BASE_YEAR;
 		}
 	}
@@ -3266,7 +3266,7 @@ bool AfterLoadGame()
 	if (IsSavegameVersionBefore(SLV_NEWGRF_LAST_SERVICE)) {
 		/* Set service date provided to NewGRF. */
 		for (Vehicle *v : Vehicle::Iterate()) {
-			v->date_of_last_service_newgrf = v->date_of_last_service;
+			v->date_of_last_service_newgrf = v->date_of_last_service.base();
 		}
 	}
 
diff --git a/src/ship_cmd.cpp b/src/ship_cmd.cpp
index 2e0186d714..a77b96fa6a 100644
--- a/src/ship_cmd.cpp
+++ b/src/ship_cmd.cpp
@@ -23,6 +23,7 @@
 #include "strings_func.h"
 #include "window_func.h"
 #include "timer/timer_game_calendar.h"
+#include "timer/timer_game_economy.h"
 #include "vehicle_func.h"
 #include "sound_func.h"
 #include "ai/ai.hpp"
@@ -902,7 +903,7 @@ CommandCost CmdBuildShip(DoCommandFlag flags, TileIndex tile, const Engine *e, V
 		v->state = TRACK_BIT_DEPOT;
 
 		v->SetServiceInterval(Company::Get(_current_company)->settings.vehicle.servint_ships);
-		v->date_of_last_service = TimerGameCalendar::date;
+		v->date_of_last_service = TimerGameEconomy::date;
 		v->date_of_last_service_newgrf = TimerGameCalendar::date;
 		v->build_year = TimerGameCalendar::year;
 		v->sprite_cache.sprite_seq.Set(SPR_IMG_QUERY);
diff --git a/src/timer/timer_game_calendar.cpp b/src/timer/timer_game_calendar.cpp
index a30ff2bc8d..bcbef27820 100644
--- a/src/timer/timer_game_calendar.cpp
+++ b/src/timer/timer_game_calendar.cpp
@@ -114,7 +114,6 @@ void TimerManager<TimerGameCalendar>::Elapsed([[maybe_unused]] TimerGameCalendar
 		TimerGameCalendar::year--;
 		days_this_year = TimerGameCalendar::IsLeapYear(TimerGameCalendar::year) ? CalendarTime::DAYS_IN_LEAP_YEAR : CalendarTime::DAYS_IN_YEAR;
 		TimerGameCalendar::date -= days_this_year;
-		for (Vehicle *v : Vehicle::Iterate()) v->ShiftDates(-days_this_year);
 		for (LinkGraph *lg : LinkGraph::Iterate()) lg->ShiftDates(-days_this_year);
 	}
 }
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 848a1bad4e..5d847c5d8f 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -38,6 +38,7 @@
 #include "train_cmd.h"
 #include "misc_cmd.h"
 #include "timer/timer_game_calendar.h"
+#include "timer/timer_game_economy.h"
 
 #include "table/strings.h"
 #include "table/train_sprites.h"
@@ -653,7 +654,7 @@ static CommandCost CmdBuildRailWagon(DoCommandFlag flags, TileIndex tile, const
 
 		v->railtype = rvi->railtype;
 
-		v->date_of_last_service = TimerGameCalendar::date;
+		v->date_of_last_service = TimerGameEconomy::date;
 		v->date_of_last_service_newgrf = TimerGameCalendar::date;
 		v->build_year = TimerGameCalendar::year;
 		v->sprite_cache.sprite_seq.Set(SPR_IMG_QUERY);
@@ -787,7 +788,7 @@ CommandCost CmdBuildRailVehicle(DoCommandFlag flags, TileIndex tile, const Engin
 		v->railtype = rvi->railtype;
 
 		v->SetServiceInterval(Company::Get(_current_company)->settings.vehicle.servint_trains);
-		v->date_of_last_service = TimerGameCalendar::date;
+		v->date_of_last_service = TimerGameEconomy::date;
 		v->date_of_last_service_newgrf = TimerGameCalendar::date;
 		v->build_year = TimerGameCalendar::year;
 		v->sprite_cache.sprite_seq.Set(SPR_IMG_QUERY);
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index 0bf1e4a163..5f01b96aff 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -170,7 +170,7 @@ void VehicleServiceInDepot(Vehicle *v)
 	SetWindowDirty(WC_VEHICLE_DETAILS, v->index); // ensure that last service date and reliability are updated
 
 	do {
-		v->date_of_last_service = TimerGameCalendar::date;
+		v->date_of_last_service = TimerGameEconomy::date;
 		v->date_of_last_service_newgrf = TimerGameCalendar::date;
 		v->breakdowns_since_last_service = 0;
 		v->reliability = v->GetEngine()->reliability;
@@ -197,7 +197,7 @@ bool Vehicle::NeedsServicing() const
 	const Company *c = Company::Get(this->owner);
 	if (this->ServiceIntervalIsPercent() ?
 			(this->reliability >= this->GetEngine()->reliability * (100 - this->GetServiceInterval()) / 100) :
-			(this->date_of_last_service + this->GetServiceInterval() >= TimerGameCalendar::date)) {
+			(this->date_of_last_service + this->GetServiceInterval() >= TimerGameEconomy::date)) {
 		return false;
 	}
 
@@ -767,9 +767,9 @@ uint32_t Vehicle::GetGRFID() const
  * This is useful if the date has been modified with the cheat menu.
  * @param interval Number of days to be added or substracted.
  */
-void Vehicle::ShiftDates(TimerGameCalendar::Date interval)
+void Vehicle::ShiftDates(TimerGameEconomy::Date interval)
 {
-	this->date_of_last_service = std::max(this->date_of_last_service + interval, TimerGameCalendar::Date(0));
+	this->date_of_last_service = std::max(this->date_of_last_service + interval, TimerGameEconomy::Date(0));
 	/* date_of_last_service_newgrf is not updated here as it must stay stable
 	 * for vehicles outside of a depot. */
 }
diff --git a/src/vehicle_base.h b/src/vehicle_base.h
index cd0ac70aae..b2b27e324b 100644
--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -287,8 +287,8 @@ public:
 	TimerGameCalendar::Year build_year;           ///< Year the vehicle has been built.
 	TimerGameCalendar::Date age;                  ///< Age in days
 	TimerGameCalendar::Date max_age;              ///< Maximum age
-	TimerGameCalendar::Date date_of_last_service; ///< Last date the vehicle had a service at a depot.
-	TimerGameCalendar::Date date_of_last_service_newgrf; ///< Last date the vehicle had a service at a depot, unchanged by the date cheat to protect against unsafe NewGRF behavior.
+	TimerGameEconomy::Date date_of_last_service; ///< Last economy date the vehicle had a service at a depot.
+	TimerGameCalendar::Date date_of_last_service_newgrf; ///< Last calendar date the vehicle had a service at a depot, unchanged by the date cheat to protect against unsafe NewGRF behavior.
 	uint16_t reliability;                 ///< Reliability.
 	uint16_t reliability_spd_dec;         ///< Reliability decrease speed.
 	byte breakdown_ctr;                 ///< Counter for managing breakdown events. @see Vehicle::HandleBreakdown
@@ -571,7 +571,7 @@ public:
 	 */
 	virtual void OnNewDay() {};
 
-	void ShiftDates(TimerGameCalendar::Date interval);
+	void ShiftDates(TimerGameEconomy::Date interval);
 
 	/**
 	 * Crash the (whole) vehicle chain.
diff --git a/src/vehicle_gui.cpp b/src/vehicle_gui.cpp
index de7bdb479a..4226d99ef6 100644
--- a/src/vehicle_gui.cpp
+++ b/src/vehicle_gui.cpp
@@ -2431,7 +2431,7 @@ struct VehicleDetailsWindow : Window {
 
 			case WID_VD_SERVICING_INTERVAL:
 				SetDParamMaxValue(0, MAX_SERVINT_DAYS); // Roughly the maximum interval
-				SetDParamMaxValue(1, TimerGameCalendar::DateAtStartOfYear(CalendarTime::MAX_YEAR)); // Roughly the maximum year
+				SetDParamMaxValue(1, TimerGameEconomy::DateAtStartOfYear(EconomyTime::MAX_YEAR)); // Roughly the maximum year
 				size->width = std::max(
 					GetStringBoundingBox(STR_VEHICLE_DETAILS_SERVICING_INTERVAL_PERCENT).width,
 					GetStringBoundingBox(STR_VEHICLE_DETAILS_SERVICING_INTERVAL_DAYS).width