from datetime import datetime
from typing import List


def get_days_in_week(timestamp: datetime) -> List[datetime]:
    """return all days in the week of `timestamp`. Week start on Monday"""
    year, week, weekday = timestamp.isocalendar()
    days = [
        datetime.strptime(f"{year} {week} {weekday}", "%G %V %u")
        for weekday in range(1, 8)
    ]
    return days