Recognised as Date
18 May 1580
- Sunday
- Q2
- Leap year
- Week 20
- Taurus
18 May 1580 falls on a Sunday in the proleptic Gregorian calendar, which did not yet exist at the time. It was day 139 of 366 in 1580, a leap year, falling in week 20 and quarter 2. Its Unix timestamp is -12,295,324,800.
Calendar position
Day of the weekSundayproleptic Gregorian; contemporaries used the Julian calendar and would have named a different day
Day of the month18th
Day of the year139 of 366
Days remaining in the year227
Days elapsed in the year138
ISO week numberWeek 20ISO 8601, weeks start on Monday
Week of the month3rd
Occurrence in the month3rd Sunday
MonthMay (month 5 of 12)
QuarterQ2 1580
Year1580
Days in the month31
Leap yearYes, 366 days
This date in other formats
ISO 86011580-05-18
British (D/M/Y)18/05/1580
American (M/D/Y)05/18/1580
Long formSunday 18th May 1580
RFC 2822Sun, 18 May 1580 00:00:00 GMT
Compact15800518
In wordsthe 18th of May, one thousand, five hundred and eighty
Julian calendar equivalent8 May 1580the date contemporaries would have written, before the Gregorian calendar existed
This date in other calendars
Hebrew23 Iyyar 5340the Hebrew calendar has been fully algorithmic since the ninth century, so this is exact
Islamic (tabular)23 Rabi I 988 AHthe tabular reckoning; the calendar in religious use begins each month on an actual crescent sighting, so expect a day either way
Persian (arithmetic)28 Ordibehesht 959the arithmetic (Birashk) calendar; the official Solar Hijri calendar takes its new year from the astronomical equinox at Tehran
Rata Die576,856days since 1 January 1 CE in the proleptic Gregorian calendar, the pivot every conversion here runs through
Unix time & day counts
Unix timestamp-12,295,324,800seconds since 1 January 1970, midnight UTC
Unix timestamp (ms)-12,295,324,800,000
Relationship to the epoch142,307 days before the Unix epoch
Julian Day Number2,298,281midnight UTC
Days since 1 January 1900-116,740
Days since 1 January 2000-153,264
Relative to today
These values depend on today’s date and change daily.
Today15 September 2026
Days ago163,018 days
In other terms446 years, 116 days and 12 hours
Weeks23288.3 weeks ago
Anniversary this year120 days ago
Years elapsed446 complete years
Seasons & signs
Zodiac signTaurusEarth sign
Chinese zodiac yearDragonthe animal changes at Chinese New Year, not 1 January
Season (Northern Hemisphere)Springmeteorological seasons, by whole months
Season (Southern Hemisphere)Autumn
Easter Sunday that year13 April 1580
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