import re

def convert_time_to_sec(time):
    # validate format
    if time == '':
        time = '00:00:00'

    time_to_array = re.split(':', time)

    hours   = float(time_to_array[0]) * 60. * 60.
    minutes = float(time_to_array[1]) * 60.
    seconds = float(time_to_array[2])

    total_time = hours + minutes + seconds

    return total_time