Today, Saturday, September 26, 2026, is day 269 of 2026: Julian date 26269 (YYYYDDD 2026269). The astronomical Julian Date at 0h UT is 2,461,309.5, and the Julian Day Number that begins at noon UT today is 2,461,310.
“Julian date” means either an astronomer's running day count (JD) or a day-of-year code such as 26269; the box above shows both for today. This converter turns any calendar date into the astronomical Julian Date (JD), Julian Day Number (JDN) and Modified Julian Date (MJD), and into the YYDDD, YYYYDDD and YDDD day-of-year codes printed on packaging and military forms. It converts back the other way, too — useful if you are reading a pack date, filling in an Army document number or checking an observation time.
How to use this calculator
- Pick what you have: a calendar date, an astronomical Julian Date, or a day-of-year code.
- For a date, enter it (it defaults to today) and optionally a time in Universal Time. The JD day starts at noon UT, so leave 12 to get a whole number.
- Read the JD, JDN and MJD, the day of the year and each ordinal code, plus the same day's date on the old Julian calendar.
- For a code, type 5 digits (YYDDD, read as 20YY) or 7 digits (YYYYDDD). Day numbers past 365 in a common year are rejected.
Three kinds of “Julian date”
1. Astronomical Julian Date (JD)
The U.S. Naval Observatory defines Julian dates as “a continuous count of days and fractions since noon Universal Time on January 1, 4713 BC (on the Julian calendar).” Fractions are the time of day: 6 pm UT is 0.25 of a day after noon. The Julian Day Number is the whole-number part, the day that begins at noon.
2. Ordinal date (day of year)
In manufacturing, food packaging and the military, “Julian date” usually means the day of the year, 001 to 365 or 366, often with the year in front. Today's is 26269 (two-digit year) or 2026269 (four-digit year). Strictly this is an ordinal date, not a Julian date, but the name is standard on the shop floor.
3. The Julian calendar
The Julian calendar has a leap year every four years without exception. The Gregorian calendar, introduced by Pope Gregory XIII in 1582, drops the leap day in century years unless they divide by 400 (USNO, Introduction to Calendars). USNO's converter uses the Julian calendar up to 4 October 1582 and the Gregorian calendar from 15 October 1582, the next day.
Formulas
JD = days since 1 January 1970 0h UT + 2,440,587.5. The calculator counts days with the proleptic Gregorian calendar, then adds the fraction for the time of day. It matches the USNO worked example (11 August 1877 at 7:30 UT = JD 2,406,842.8125) and NASA Goddard's table (1 January 2010, 0h UT = JD 2,455,197.5).
- JDN = JD at noon UT on the date = JD at 0h + 0.5.
- MJD = JD − 2,400,000.5 (USNO).
- Day of year = days since January 1 of the same year + 1.
- YYDDD = last two digits of the year, then the day of year padded to three digits. YDDD uses only the last digit of the year.
Worked examples
Today at 6 pm UT
September 26, 2026 at 0h UT is JD 2,461,309.5. Adding 18 hours (0.75 of a day) gives JD 2,461,310.25, MJD 61,309.75.
March 15, 2026 as a packaging code
January (31) + February (28) + 15 = day 74, so the code is 26074 or 2026074. In a leap year such as 2028 the same date is day 75.
Reading code 24366
2024 was a leap year, so day 366 exists: it is December 31, 2024. Code 25366 is invalid because 2025 had 365 days.
The 1582 switch
4 October 1582 on the Julian calendar is JD 2,299,159.5 at 0h UT, and the next day was 15 October 1582 on the Gregorian calendar, JD 2,299,160.5 (USNO). The Julian Day count kept running without a gap even though 10 calendar dates were skipped.
Julian Date on January 1 of each year
JD at 0h UT on January 1 and the JDN that starts at noon that day. Add the day of year − 1 to get any other date.
| Year | JD (Jan 1, 0h UT) | JDN | MJD | Days in year |
|---|---|---|---|---|
| 2020 | 2,458,849.5 | 2,458,850 | 58,849 | 366 |
| 2021 | 2,459,215.5 | 2,459,216 | 59,215 | 365 |
| 2022 | 2,459,580.5 | 2,459,581 | 59,580 | 365 |
| 2023 | 2,459,945.5 | 2,459,946 | 59,945 | 365 |
| 2024 | 2,460,310.5 | 2,460,311 | 60,310 | 366 |
| 2025 | 2,460,676.5 | 2,460,677 | 60,676 | 365 |
| 2026 | 2,461,041.5 | 2,461,042 | 61,041 | 365 |
| 2027 | 2,461,406.5 | 2,461,407 | 61,406 | 365 |
| 2028 | 2,461,771.5 | 2,461,772 | 61,771 | 366 |
| 2029 | 2,462,137.5 | 2,462,138 | 62,137 | 365 |
| 2030 | 2,462,502.5 | 2,462,503 | 62,502 | 365 |
| 2031 | 2,462,867.5 | 2,462,868 | 62,867 | 365 |
| 2032 | 2,463,232.5 | 2,463,233 | 63,232 | 366 |
| 2033 | 2,463,598.5 | 2,463,599 | 63,598 | 365 |
| 2034 | 2,463,963.5 | 2,463,964 | 63,963 | 365 |
| 2035 | 2,464,328.5 | 2,464,329 | 64,328 | 365 |
Julian date codes for common dates
Day-of-year numbers and the five-digit code for fixed dates this year, with the day number they take in a leap year (2028) for comparison.
| Date | Day (2026) | Code 2026 | Day in a leap year |
|---|---|---|---|
| New Year's Day | 1 | 26001 | 1 |
| Valentine's Day | 45 | 26045 | 45 |
| March 1 | 60 | 26060 | 61 |
| April 15 | 105 | 26105 | 106 |
| July 4 | 185 | 26185 | 186 |
| September 1 | 244 | 26244 | 245 |
| October 31 | 304 | 26304 | 305 |
| December 25 | 359 | 26359 | 360 |
| December 31 | 365 | 26365 | 366 |
Day-of-year calendar for 2026
Find the day in the left column and the month across the top. 2026 is not a leap year, so December 31 is day 365.
| Day | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 001 | 032 | 060 | 091 | 121 | 152 | 182 | 213 | 244 | 274 | 305 | 335 |
| 2 | 002 | 033 | 061 | 092 | 122 | 153 | 183 | 214 | 245 | 275 | 306 | 336 |
| 3 | 003 | 034 | 062 | 093 | 123 | 154 | 184 | 215 | 246 | 276 | 307 | 337 |
| 4 | 004 | 035 | 063 | 094 | 124 | 155 | 185 | 216 | 247 | 277 | 308 | 338 |
| 5 | 005 | 036 | 064 | 095 | 125 | 156 | 186 | 217 | 248 | 278 | 309 | 339 |
| 6 | 006 | 037 | 065 | 096 | 126 | 157 | 187 | 218 | 249 | 279 | 310 | 340 |
| 7 | 007 | 038 | 066 | 097 | 127 | 158 | 188 | 219 | 250 | 280 | 311 | 341 |
| 8 | 008 | 039 | 067 | 098 | 128 | 159 | 189 | 220 | 251 | 281 | 312 | 342 |
| 9 | 009 | 040 | 068 | 099 | 129 | 160 | 190 | 221 | 252 | 282 | 313 | 343 |
| 10 | 010 | 041 | 069 | 100 | 130 | 161 | 191 | 222 | 253 | 283 | 314 | 344 |
| 11 | 011 | 042 | 070 | 101 | 131 | 162 | 192 | 223 | 254 | 284 | 315 | 345 |
| 12 | 012 | 043 | 071 | 102 | 132 | 163 | 193 | 224 | 255 | 285 | 316 | 346 |
| 13 | 013 | 044 | 072 | 103 | 133 | 164 | 194 | 225 | 256 | 286 | 317 | 347 |
| 14 | 014 | 045 | 073 | 104 | 134 | 165 | 195 | 226 | 257 | 287 | 318 | 348 |
| 15 | 015 | 046 | 074 | 105 | 135 | 166 | 196 | 227 | 258 | 288 | 319 | 349 |
| 16 | 016 | 047 | 075 | 106 | 136 | 167 | 197 | 228 | 259 | 289 | 320 | 350 |
| 17 | 017 | 048 | 076 | 107 | 137 | 168 | 198 | 229 | 260 | 290 | 321 | 351 |
| 18 | 018 | 049 | 077 | 108 | 138 | 169 | 199 | 230 | 261 | 291 | 322 | 352 |
| 19 | 019 | 050 | 078 | 109 | 139 | 170 | 200 | 231 | 262 | 292 | 323 | 353 |
| 20 | 020 | 051 | 079 | 110 | 140 | 171 | 201 | 232 | 263 | 293 | 324 | 354 |
| 21 | 021 | 052 | 080 | 111 | 141 | 172 | 202 | 233 | 264 | 294 | 325 | 355 |
| 22 | 022 | 053 | 081 | 112 | 142 | 173 | 203 | 234 | 265 | 295 | 326 | 356 |
| 23 | 023 | 054 | 082 | 113 | 143 | 174 | 204 | 235 | 266 | 296 | 327 | 357 |
| 24 | 024 | 055 | 083 | 114 | 144 | 175 | 205 | 236 | 267 | 297 | 328 | 358 |
| 25 | 025 | 056 | 084 | 115 | 145 | 176 | 206 | 237 | 268 | 298 | 329 | 359 |
| 26 | 026 | 057 | 085 | 116 | 146 | 177 | 207 | 238 | 269 | 299 | 330 | 360 |
| 27 | 027 | 058 | 086 | 117 | 147 | 178 | 208 | 239 | 270 | 300 | 331 | 361 |
| 28 | 028 | 059 | 087 | 118 | 148 | 179 | 209 | 240 | 271 | 301 | 332 | 362 |
| 29 | 029 | 088 | 119 | 149 | 180 | 210 | 241 | 272 | 302 | 333 | 363 | |
| 30 | 030 | 089 | 120 | 150 | 181 | 211 | 242 | 273 | 303 | 334 | 364 | |
| 31 | 031 | 090 | 151 | 212 | 243 | 304 | 365 |
Common mistakes
- Mixing up the three meanings. A code like 26269 is a day of year; a number like 2,461,310 is an astronomical Julian Day. Neither is a date on the Julian calendar.
- Forgetting leap years. From March 1 on, every day-of-year number is one higher in a leap year.
- Local time vs UT. Julian Dates are in Universal Time. 9 pm in New York during daylight saving time (UTC−4) is already the next UT day.
- Treating JD as starting at midnight. A whole JD number falls at noon UT; midnight ends in .5.
- Reading a pack date as an expiry date. A Julian code on eggs or cans shows when the item was packed, not when it goes off.
To count days between two calendar dates, use the days from today calculator; for 24-hour times, the military time converter.
Frequently asked questions
What is the Julian date today?
It depends which "Julian date" you mean. As a day-of-year code, today (September 26, 2026 when this page was built) is 26269, or 2026269 with a four-digit year. As an astronomical Julian Date it is 2,461,309.5 at midnight UT. The calculator shows your own today.
What is a Julian calendar date?
Three different things share the name. (1) The astronomical Julian Date (JD), a running count of days since noon Universal Time on 1 January 4713 BC, used by astronomers (USNO). (2) The ordinal date or day-of-year code such as 26269, used on food packaging and in military logistics. (3) A date on the Julian calendar, the Roman calendar replaced by the Gregorian calendar from 1582, which today runs 13 days behind.
How do I convert a Julian date to a calendar date?
For a day-of-year code like 26045, split off the year (26 = 2026) and the day (045), then count 45 days from January 1: February 14, 2026. For an astronomical JD, subtract 2440587.5 to get days since 1 January 1970 0h UT, or enter it in the calculator above.
How do I read a Julian date code on food packaging?
The last three digits are the day of the year the item was packed: 001 is January 1 and 365 (366 in a leap year) is December 31. Egg cartons with the USDA grade shield show the pack date this way, per the U.S. Army Public Health Center food dating guide. Digits before it, if any, are usually the year; other letters are plant or lot codes.
What does a military Julian date look like?
On U.S. Army supply document numbers the Julian date is four digits: the last digit of the year followed by the three-digit day of the year. PS Magazine's example: a request completed 14 July 2006 has Julian date 6195. Today's would be 6269.
What day of the year is it?
On September 26, 2026 it is day 269 of 2026, with 96 days left. In a leap year every date from March 1 on has a number one higher, so the same code can mean different dates in different years — always check which year it belongs to. The day-of-year calendar below gives every date.
Why does the Julian Date end in .5 at midnight?
Because the USNO definition counts days from noon Universal Time, not midnight. A whole JD number falls at noon UT and midnight ends in .5: 1 January 2000 at 0h UT is JD 2,451,544.5, and noon that day is JD 2,451,545.0.
What is the Modified Julian Date (MJD)?
MJD = JD − 2400000.5 (USNO). It starts at midnight instead of noon and uses smaller numbers: MJD 0 is 17 November 1858, 0h UT, and September 26, 2026 is MJD 61,309.
What is J2000?
J2000.0 is the standard astronomical reference epoch: Julian Date 2,451,545.0 TT, which is 2000 January 1 at 12h Terrestrial Time (about 11:58:56 UTC), per the U.S. Naval Observatory.
How far apart are the Julian and Gregorian calendars?
13 days at present. The Julian calendar adds a leap day every 4 years; the Gregorian calendar skips it in century years not divisible by 400 (USNO). The gap was 10 days when the Gregorian calendar started on 15 October 1582, and grows to 14 days from 1 March 2100 (Gregorian).
Sources & method
- U.S. Naval Observatory — Julian Date Converter (definition, JD epoch, MJD = JD − 2400000.5, 1582 calendar switch)
- U.S. Naval Observatory — Converting between Julian dates and Gregorian calendar dates (formula and worked example)
- U.S. Naval Observatory — Terrestrial Time: J2000.0 = JD 2451545.0 TT (2000 January 1, 12h TT)
- U.S. Naval Observatory — Introduction to calendars (Julian and Gregorian leap-year rules)
- NASA Goddard (D. Simpson) — Julian Days 2010 table, 0h UT
- U.S. Army PS Magazine 646 (Sept 2006) — Creating document numbers: Julian date = last digit of year + day of year
- U.S. Army Public Health Center / DeCA — Food product dating brochure: egg pack date is a 3-digit Julian date, 001–365
- University of Arizona Cooperative Extension AZ1666 — Food product dating (Julian date on egg cartons)
Results are estimates for general information. Found an error? It helps everyone — see our methodology.