Linked from

The 45 pages that link to Julian calendar, each with the reason it gives.

• Julius CaesarBroader topic: The calendar reform was one of Caesar’s lasting administrative changes.

• Gregorian calendarCompared with: Its slightly long average year caused the seasonal drift the Gregorian reform addressed.

• Tropical yearCompared with: Its average year is too long to stay aligned with the tropical year.

• EquinoxRelated: Its year was slightly too long, causing seasonal dates and equinoxes to drift.

• Roman CalendarBroader topic: It was the Roman calendar’s decisive reform and became the basis of later European calendars.

• IntercalationRelated: It replaced irregular Roman adjustments with a predictable intercalation cycle.

• Leap yearCompared with: Its simpler rule drifts against the seasons faster than the Gregorian rule.

• CalendarBroader topic: Its simple leap-year cycle gradually displaced dates from the seasons.

• Metonic cycleCompared with: Rome abandoned lunisolar reckoning entirely, making the cycle unnecessary for the civic year.

• Anno DominiRelated: Anno Domini year numbers first circulated in a Julian calendar context.

• Pope Gregory XIIICompared with: Its gradual drift from the solar year prompted Gregory’s calendar reform.

• Calendar reformBroader topic: Its small annual excess produced the drift that prompted the Gregorian reform.

• EasterCompared with: Its use helps explain why Orthodox Easter often falls on a different date.

• Babylonian calendarCompared with: Its fixed solar year contrasts with Babylonian reliance on lunar months.

• Bulgarian Orthodox ChurchRelated: The church uses the Julian calendar for determining movable feast dates.

• Historical chronologyCompared with: Its dates diverge from Gregorian dates, creating conversion issues across periods.

• Egyptian calendarCompared with: Its leap-year rule corrected the seasonal drift that the Egyptian civil year allowed.

• Liturgical yearCompared with: Some churches use it for feast dates, producing differences from Gregorian observance.

• Solar yearRelated: Its average year slightly exceeded the seasonal year, shifting calendar dates over centuries.

• Dionysius ExiguusRelated: Dionysius’s tables operated within the Julian calendar rather than replacing its structure.

• June solsticeCompared with: Its longer average year caused greater seasonal-date drift than the Gregorian calendar.

• March equinoxCompared with: Its year length drifts against the equinox more quickly than the Gregorian year.

• Ab Urbe ConditaRelated: Its adoption changed Roman calendar structure, but did not make AUC the everyday dating system.

• December solsticeRelated: Its year was slightly too long, causing calendar dates of solstices to drift over centuries.

• EpiphanyRelated: Churches using the Julian calendar observe January 6 on a different date in the civil Gregorian calendar.

• JanuaryRelated: It preceded the Gregorian calendar and preserved January as the year’s first month.

• MonthRelated: It supplied the month structure later revised by the Gregorian calendar.

• Seven-day weekRelated: The Roman calendar reform retained the week while restructuring months and years.

• Solar calendarCompared with: Its slightly long average year caused seasonal dates to drift over centuries.

• Old BelieversRelated: Calendar differences shape the dates of feasts in Old Believer communities.

• BirthdayRelated: Its regular year structure made annual birth anniversaries easier to align.

• Christopher ClaviusCompared with: The Gregorian reform corrected the seasonal drift produced by its leap-year rule.

• Ethiopian calendarCompared with: It shares a four-year leap cycle but differs in structure and date alignment.

• FebruaryRelated: The Gregorian calendar retained February’s leap day while refining the Julian rule.

• Seleucid eraCompared with: It supplies a calendar framework, whereas the Seleucid era supplies a year-numbering epoch.

• Astronomical year numberingRelated: Astronomical year numbering also labels Julian dates, independently of which calendar’s rules apply.

• AprilRelated: April retained its 30 days under the calendar that preceded the Gregorian system.

• DecemberRelated: It retained December as the final month before the Gregorian reform.

• History of calendarsBroader topic: Its leap-year rule simplified Roman timekeeping but slightly overestimated the solar year.

• JulyRelated: Its reform established the calendar system from which July’s place derives.

• Ante Christum natumRelated: Ancient dates expressed with this phrase are often reconstructed using the Julian calendar.

• Era of the MartyrsRelated: The Coptic calendar inherits its month structure and leap-year rhythm from this calendar.

• New YearRelated: It carried the January 1 year boundary into the calendar later revised by Gregory XIII.

• Phantom time conspiracy theoryRelated: The hypothesis disputes how calendar dates align with elapsed astronomical time.

• Year (calendar)Compared with: Its simpler leap-year rule makes its average year longer than the Gregorian year.