diff --git a/zfoo/scheduler/SchedulerBus.gd b/zfoo/scheduler/SchedulerBus.gd
index f49cbdf..d57921c 100644
--- a/zfoo/scheduler/SchedulerBus.gd
+++ b/zfoo/scheduler/SchedulerBus.gd
@@ -9,12 +9,21 @@ const CollectionUtils = preload("res://zfoo/util/CollectionUtils.gd")
 
 const schedulerMap: Dictionary = {}
 
+
+# 固定延迟执行的任务，delay默认为毫秒
 static func schedule(runnable: Runnable, delay: int) -> void:
 	var triggerTimestamp = TimeUtils.currentTimeMillis() + delay
 	var definition = SchedulerDefinition.new(runnable, delay, triggerTimestamp, false)
 	schedulerMap[definition] = null
 
 
+# 不断执行的周期循环任务，delay默认为毫秒
+static func scheduleAtFixRate(runnable: Runnable, delay: int) -> void:
+	var triggerTimestamp = TimeUtils.currentTimeMillis() + delay
+	var definition = SchedulerDefinition.new(runnable, delay, triggerTimestamp, false)
+	schedulerMap[definition] = null
+
+
 static func triggerPerSecond() -> void:
 	var timestamp = TimeUtils.currentTimeMillis()
 	
diff --git a/zfoo/scheduler/TimeUtils.gd b/zfoo/scheduler/TimeUtils.gd
index f729154..4c44788 100644
--- a/zfoo/scheduler/TimeUtils.gd
+++ b/zfoo/scheduler/TimeUtils.gd
@@ -1,5 +1,20 @@
 extends Object
 
+
+# 一秒钟对应的纳秒数
+const NANO_PER_SECOND: int = 1_000_000_000
+# 一秒钟对应的毫秒数
+const MILLIS_PER_SECOND: int = 1 * 1000
+# 一分钟对应的毫秒数
+const MILLIS_PER_MINUTE = 1 * 60 * MILLIS_PER_SECOND
+# 一个小时对应的毫秒数
+const MILLIS_PER_HOUR = 1 * 60 * MILLIS_PER_MINUTE
+# 一天对应的毫秒数
+const MILLIS_PER_DAY = 1 * 24 * MILLIS_PER_HOUR
+# 一周对应的毫秒数
+const MILLIS_PER_WEEK = 1 * 7 * MILLIS_PER_HOUR
+
+
 const timestamp = [0]