def calculate_speaker_ages(speakers, dobs, rec_date):
    """
    Calculate the age in days of a list of speakers based on recording date and DoB

    inputs: (list of speakers, DoB dictionary of datetimes, recording datetime)
    output: list of speaker ages
    """
    set_speakers = set(speakers)
    age_dict = {}
    for s in set_speakers:
        dob = dobs[s]
        delta_days = abs((rec_date - dob).days)
        age_dict[s] = delta_days
    speaker_ages = [age_dict[s] for s in speakers]
    return speaker_ages