calculate_dst.py

import pytz
from dateutil import rrule
from datetime import datetime


def generate_dst_dates(year):
    tz = pytz.timezone("America/New_York")
    dst_start_date = list(
        rrule.rrule(
            rrule.YEARLY,
            dtstart=datetime(year, 3, 8, 2, 0, 0),
            until=datetime(year, 12, 31),
            bymonth=3,
            byweekday=rrule.SU(2),
        )
    )[0]
    dst_end_date = list(
        rrule.rrule(
            rrule.YEARLY,
            dtstart=datetime(year, 11, 1, 2, 0, 0),
            until=datetime(year, 12, 31),
            bymonth=11,
            byweekday=rrule.SU(1),
        )
    )[0]

    dst_start_date = tz.localize(dst_start_date)
    dst_end_date = tz.localize(dst_end_date)

    return dst_start_date, dst_end_date


def get_dst_timestamps(year):
    tz = pytz.timezone("UTC")
    epoch = tz.localize(datetime(2023, 1, 1, 0, 0, 0))

    dst_start_date, dst_end_date = generate_dst_dates(year)
    dst_start_timestamp = int(dst_start_date.timestamp()) - int(epoch.timestamp())
    dst_end_timestamp = int(dst_end_date.timestamp()) - int(epoch.timestamp())

    return dst_start_timestamp, dst_end_timestamp


def get_hex_string_for_years(start_year, num_years):
    result = []
    for year in range(start_year, start_year + num_years):
        start_timestamp, end_timestamp = get_dst_timestamps(year)
        result.append(
            hex(start_timestamp)[2:].zfill(8)
        )
        result.append(hex(end_timestamp)[2:].zfill(8))
    return "".join(result)


print(get_hex_string_for_years(2023, 101))