diff --git a/code/controllers/subsystem/timer.dm b/code/controllers/subsystem/timer.dm
index 4bbc44c218a..3e7285a79bf 100644
--- a/code/controllers/subsystem/timer.dm
+++ b/code/controllers/subsystem/timer.dm
@@ -1,5 +1,5 @@
 #define BUCKET_LEN (world.fps*1*60) //how many ticks should we keep in the bucket. (1 minutes worth)
-#define BUCKET_POS(timer) ((round((timer.timeToRun - SStimer.head_offset) / world.tick_lag) % BUCKET_LEN)||BUCKET_LEN)
+#define BUCKET_POS(timer) (((round((timer.timeToRun - SStimer.head_offset) / world.tick_lag)+1) % BUCKET_LEN)||BUCKET_LEN)
 #define TIMER_MAX (world.time + TICKS2DS(min(BUCKET_LEN-(SStimer.practical_offset-DS2TICKS(world.time - SStimer.head_offset))-1, BUCKET_LEN-1)))
 #define TIMER_ID_MAX (2**24) //max float with integer precision
 
@@ -122,7 +122,7 @@ SUBSYSTEM_DEF(timer)
 	if(!resumed)
 		timer = null
 
-	while(practical_offset <= BUCKET_LEN && head_offset + (practical_offset*world.tick_lag) <= world.time)
+	while(practical_offset <= BUCKET_LEN && head_offset + ((practical_offset-1)*world.tick_lag) <= world.time)
 		var/datum/timedevent/head = bucket_list[practical_offset]
 		if(!timer || !head || timer == head)
 			head = bucket_list[practical_offset]
@@ -170,7 +170,7 @@ SUBSYSTEM_DEF(timer)
 					qdel(timer)
 				continue
 
-			if(timer.timeToRun < head_offset + TICKS2DS(practical_offset))
+			if(timer.timeToRun < head_offset + TICKS2DS(practical_offset-1))
 				bucket_resolution = null //force bucket recreation
 				CRASH("[i] Invalid timer state: Timer in long run queue that would require a backtrack to transfer to short run queue. [get_timer_debug_string(timer)] world.time: [world.time], head_offset: [head_offset], practical_offset: [practical_offset]")
 				if(timer.callBack && !timer.spent)
@@ -521,4 +521,4 @@ SUBSYSTEM_DEF(timer)
 #undef BUCKET_LEN
 #undef BUCKET_POS
 #undef TIMER_MAX
-#undef TIMER_ID_MAX
\ No newline at end of file
+#undef TIMER_ID_MAX