code: def get_default_origin_for_time_vars(df, time_col):
      """Sets default value for origin_for_time_vars
  
      Parameters
      ----------
      df : `pandas.DataFrame`
          Training data. A data frame which includes the timestamp and value columns
      time_col : `str`
          The column name in `df` representing time for the time series data.
  
      Returns
      -------
      dt_continuous_time : `float`
          The time origin used to create continuous variables for time
      """
      date = pd.to_datetime(df[time_col].iloc[0])
      return convert_date_to_continuous_time(date)
  
imports: import math
  from datetime import datetime
  from datetime import timedelta
  import numpy
  import pandas
  import pytz
  from holidays_ext import get_holidays
  from pandas.tseries.frequencies import to_offset
  from scipy.special import expit
  from greykite.common import constants
  from greykite.common.python_utils import split_offset_str
label_desc: Use image node_id 2 for calling a global function with example usage: get_default_origin_for_time_vars(df, time_col) and returns: convert_date_to_continuous_time