57 lines
1.6 KiB
Python
57 lines
1.6 KiB
Python
# tools/julian.py
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from datetime import datetime, timedelta
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import math
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def julian_date(date: datetime | None = None) -> float:
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"""Given any date in the future or past, return julian date"""
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if date is None:
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date = datetime.now()
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time_ms = date.timestamp() * 1000
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return (time_ms / 86400000) + 2440587.5
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def CJDN(date: datetime | None = None) -> int:
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return round(julian_date(date))
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def current_julian_date() -> float:
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"""Returns current julian date"""
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return julian_date()
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def tomorrow_julian_date() -> float:
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"""returns tomorrow's julian date"""
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date = datetime.now() + timedelta(days=1)
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return julian_date(date)
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def future_julian_date(
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hoursadd: int = 0, minutesadd: int = 0, secondsadd: int = 0
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) -> float:
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"""defaults to current if no specifications made. HOURS, MINUTES, AND SECONDS CANNOT BE NEGATIVE"""
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date = datetime.now() + timedelta(
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hours=hoursadd, minutes=minutesadd, seconds=secondsadd
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)
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return julian_date(date)
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def epoch_days(date: datetime | None = None) -> float:
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"""returns days since Jan 1st, 2000. Negative if before this date"""
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return julian_date(date) - 2451545.0
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def day_percent(date: datetime | None = None) -> float:
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"""Returns decimal portion of Julian Date"""
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whole = julian_date(date)
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return whole - math.floor(whole)
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def from_julian(j: float) -> datetime:
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"""Returns datetime.datetime object given julian date J"""
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J1970 = 2440588.0
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dayMs = 24 * 60 * 60 * 1000
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return datetime.fromtimestamp((j + 0.5 - J1970) * dayMs / 1000.0)
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