text: from .equation_of_center import equation_of_center
  from .mean_longitude import mean_longitude
  
  
  def true_longitude(t: float) -> float:
      """
      Calculate the sun's true longitude in decimal degrees.
  
      Parameters:
          t (float): The time in Julian Centuries (36525 days) since J2000.0
  
      Returns:
          float: The sun's true longitude at the given time
      """
      # t must be in the range from year 1901 thru year 2099
      if (t < -0.99 or 1.00 < t):
          raise ValueError("t must be beteween -0.99 and 1.00: " + str(t))
  
      return equation_of_center(t) + mean_longitude(t)
  