yearday

• year-day, year day, year's day

From Middle English ȝereday, ȝerdai (“anniversary”), from Old English *ġēardæġ (compare Old English ġeārdagas (“days of yore”)), from Proto-West Germanic *jāradag (“day of the year, yearly day”), from Proto-Germanic *jēradagaz, equivalent to year +‎ day. Cognate with West Frisian jierdei (“birthday”), Dutch jaardag (“anniversary, birthday”), German Jahrtag (“anniversary”).

yearday (plural yeardays)

1. (rare, historical) Synonym of anniversary, a day occurring in a yearly cycle.
   • 1887, Michael Baxter, Forty coming wonders:

     The Second Advent of Christ to remove to heaven his waiting people takes place at the end of the yearday sixth vial in accordance with his personal announcement, […]

   • 1956, The Accountant's Magazine, volume 60, page 584:

     It was reported that the Vice-President and Mrs. Dowling and the Secretary and Mrs. McDougall were to represent the Scottish Institute at the Accountants' Yearday of the Nederlands Instituut van Accountants and at the Silver Jubilee celebrations in Düsseldorf […]

   • 1970, SAMT, page 881:

     The 14th Academic Yearday of the Medical Faculty of the University of Stellenbosch will be held on 6-7 August in the C. R. Louw Theatre, Sanlamhof, Bellville, Cape.

   • 1994, originally 1966, Robert Lawrence Trask, Language Change, page 198:

     In a foregoing piece (a week ago in this same mirthboke) I wrote anent the ninehundredth yearday of the Clash of Hastings; […]

   1. (rare, nonstandard) Synonym of birthday, the anniversary of one's birth.
      • 2020, Pamela L. Volpert, The Tribes of the Littles, page 31:

        Today was her grandchild's yearday. Every year on the day the Little was born, the Littles celebrated their yearday. Henna Rose wanted to prepare a special evening meal and celebration for Knotten tonight. Knotten was ten yeardays today.

   2. (rare, nonstandard) An annual day; the anniversary of an event or occasion.
      • 2020, Georg Ebers, The Historical Romances of Georg Ebers:

        To wit, on certain year-days he would tarry alone in his tower, and his lamp might be seen gleaming till midnight.

   3. Synonym of deathday or (Christianity) year's mind, the anniversary of a person's death, particularly as observed with a requiem mass or other commemoration.
      • 1907, William Page, The Victoria history of the county of Suffolk, volume 1, page 660:

        His executors were to keep his yearday for twenty years at the cost of 20s. per year, and finally after his wife's death the bailiffs and commonalty of Southwold were to find a priest for sixteen years next following to sing for his soul […]

      • 1998, Plutarch (in translation), Lives of the Noble Grecians and Romans, page 310:

        For they were the very days on the which the women celebrated the feast and yearday of Adonis' death: and there were also in divers parts of the city, images of dead men carried to burial, and women following them, mourning and lamenting.

      • 2009, Georgette Heyer, My Lord John: A tale of intrigue, honor and the rise of a king, page 56:

        The younger children remained at Bytham for a year, and saw their brothers again only at Leicester, on the yearday of Mother's death.

      • 2009, Orson Scott Card, Hart's Hope, page 75:

        So it was that one day, by chance the fourth yearday of young Orem's life, Avonap let fall his hoe when he saw the boy, let it fall and walked to where he played.

2. A particular day numbered from the first day in the year, without regard to month divisions.
   • 1985, Mathematics magazine, volume 58:

     To avoid the idiosyncracies of leap years, we propose, as a first approximation to the actual yearday, a standardized yearday s that is a function of (m, d) only, s = S(m) +dl (6) where 5 is a function of m only.

   • 1998, Australian Journal of Botany, volume 46:

     […] the amended yearday which was the middle day in flowering range. the yearday which is equivalent to commencement of flowering. the amended yearday (based on flowering yearday) which is the equivalent to the commencement of […]

   • 2000, Agricultural and forest meteorology;, volumes 104-105:

     ... T₁max the maximum (cloud-free) daily total transmittance at a location with a given elevation and near-surface water-vapor pressure on a given yearday, […]

   • 2002, Journal of physical oceanography, volume 32:

     Its power supply failed at yearday 227 (0300), […]