| PIDAY | Observance that falls on the anniversary of Einstein's birth |
| ARBOR | ___ Day (annual observance that falls on April 24 this year; our four theme entries have already planted trees in their names) |
| ULM | City of Einstein's birth |
| DIPLOMAT | The International Day of ____s takes place on the anniversary of the foundation of the UN |
| OBIT | An old boy returns to it on the anniversary of the death (4) |
| NURSES | International _ Day, celebrated worldwide on the anniversary of Florence Nightingale's birth (6) |
| REGNALYEAR | Period starting on the anniversary of an English monarch's accession |
| ARMISTICEDAY | The anniversary of the signing of the truce that ended World War I, now kept on Remembrance Sunday (9,3) |
| BASTILLE | The anniversary of the storming of this Paris prison is celebrated by France on July 14 |
| OBELISK | The Flaminio ---, taken to Rome from Heliopolis by Augustus to mark the anniversary of the conquest of Egypt (7) |
| MARCH | Month in which the anniversary of the assassination of Julius Caesar occurs |
| CINCODEMAYO | The anniversary of Mexico's victory over the French at Puebla in 1862, celebrated on May 5 (5,2,4) |
| BIRTHDAYPARTY | Social event celebrating the anniversary of the day on which a person was born (8,5) |
| PRESENTDAY | Now this might describe the anniversary of one's birth (7,3) |
| BIRTHDAY | Party type that celebrates the anniversary of your arrival |
| WASTEOFBREATH | Failure to enjoy the air? That's the sort of advice that falls on deaf ears! (5,2,6) |
| CHRISTMASSPIRIT | Enthusiasm for the holiday that falls on December 25: 2 wds. (Theme answer: The circled letters, which move left-to-right across the puzzle, spell a word in the title) |
| OCT | Mo. when Germany observes the anniversary of its reunification |
| LSD | The anniversary of its first use is called Bicycle Day |
| JANUARY | The birthday of all racehorses in the Northern Hemisphere falls on the first of this month. (7) |
