import re
from datetime import datetime


def parse_date_sentence(sentence):
    """Return the date type + date in this sentence (if one exists)."""
    #   Search for month date, year at the end of the sentence
    sentence = sentence.lower().strip()
    date_re = r".*((january|february|march|april|may|june|july|august"
    date_re += r"|september|october|november|december) \d+, \d+)$"
    match = re.match(date_re, sentence)
    if match:
        date = datetime.strptime(match.group(1), "%B %d, %Y")
        if 'comment' in sentence:
            return ('comments', date.strftime("%Y-%m-%d"))
        if 'effective' in sentence:
            return ('effective', date.strftime("%Y-%m-%d"))
        return ('other', date.strftime('%Y-%m-%d'))