vba中计算程序运行时间

Dim a As Date
Dim b As Date
a = Time
Application.ScreenUpdating = False   '''''''''''''''''''''''锁屏
Call data.dataCheck
Call data.storeFormation
Call data.datas
Call data.states
Application.ScreenUpdating = True
b = Time - a
MsgBox b                           '''''''''''''''''''''''''''''''''''输出程序运行所要花费的时间