Monday

Julian Date for January 29, 2024

Monday, January 29, 2024 is day 29 of 366 — the 29th day of 2024. Written as a Julian date it is 2024029.

Julian date (YYYYDDD)

2024029

5-digit (YYDDD)
24029
Day of year
29
Zero-padded (DDD)
029
Julian Day Number
2460339
Julian Date at 00:00 UTC
2460338.5
Modified Julian Date
60338.0

How 2024029 is built

A Julian date in the day-of-year sense is just the year followed by the day number, counted from 1 January. January 29, 2024 is the 29th day of 2024, so the code is 2024 + 029 = 2024029. Many systems drop the century and print 24029 instead.

2024 is a leap year with 366 days, so day numbers run from 001 to 366. After January 29, 2024 there are 337 days left in the year.

Careful: 24029 does not name a century

The 5-digit form 24029 only carries two digits of year, so on its own it is ambiguous. Day 29 of a year ending in 24 could equally be:

  • January 29, 2024 — the usual reading for a recent product code
  • January 29, 1924
  • January 29, 2124

If you are reading a code off packaging, the surrounding context — a shelf life of months rather than decades — almost always settles it.

Day 29 in nearby years

The same day number lands on a different calendar date depending on whether the year is a leap year. This is the single most common mistake when decoding a code whose year you had to guess.

YearJulian dateCalendar date
2021 2021029 January 29, 2021
2022 2022029 January 29, 2022
2023 2023029 January 29, 2023
2024 2024029 January 29, 2024
2025 2025029 January 29, 2025
2026 2026029 January 29, 2026
2027 2027029 January 29, 2027

Astronomical Julian Date for January 29, 2024

In astronomy, "Julian Date" means something different: a continuous count of days since noon on 1 January 4713 BC. The Julian Day Number for January 29, 2024 is 2460339 — that number covers the 24 hours from noon UTC on January 29, 2024 to noon UTC the next day.

  • JD at 00:00 UTC — 2460338.5
  • JD at 12:00 UTC — 2460339.0
  • Modified Julian Date (MJD) at 00:00 UTC — 60338.0

See Julian Day for where the count comes from, or the astronomical converter to include a time of day.

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