Helliconia Spring is a novel by Brian W. Aldiss published in 1982. It is the first part of the Helliconia trilogy, followed by Helliconia Summer (1983) and Helliconia Winter (1985).
Helliconia Spring is a novel which is set on a planet with two suns, where each year is incredibly long.

Several different calendars are mentioned in the book. The table below includes certain dates that delineate a reckoning of the passage of time.
| 1: Avernus (EY) | 2: Earth (AD) | 3: Helliconia (EYAA) | 4: Helliconia (HYAA) | 5: Ancipital | 6: Lordly | 7: After Union | 8: Events |
|---|---|---|---|---|---|---|---|
| 2092 | 5700 | 0 | 0 | ??? | N/A | N/A | Apastron |
| 2206 | 5814 | 114 | 80 | 0 | N/A | N/A | Ancipital air-turn calendar is at zero. |
| ??? | ??? | ??? | ??? | ??? | N/A | N/A | "Yuli" prelude story takes place at unspecified period before Great Spring. |
| 2663 | 6271 | 571 | 402 | 322 | 0 | N/A | Wall Ein Den becomes lord of Embruddock. |
| 2689 | 6297 | 597 | 420 | 340 | 18 | 0 | Wall Ein Den has ruled Embruddock for 18 years. Little Yuli and Dresyl conquer the town and unite the two tribes. |
| 2693 | 6301 | 601 | 423 | 343 | 21 | 3 | Loilanun is born. |
| 2695 | 6303 | 603 | 425 | 345 | 23 | 5 | Aoz Roon is born. |
| 2707 | 6315 | 615 | 433 | 353 | 31 | 13 | Laintal Ay is born. Great phagor crusade begins 13-year march toward Oldorando. |
| 2713 | 6321 | 621 | 437 | 357 | 35 | 17 | Dly Hoin dies. Dresyl dies shortly afterward. |
| 2715 | 6323 | 623 | 439 | 359 | 37 | 19 | "Embruddock" story begins. Little Yuli dies aged 29 (about 41 in Earth-years). Aoz Roon is 14 (about 20 in Earth-years). Laintal Ay is 6 (about 8 in Earth-years). |
| 2718 | 6326 | 626 | 441 | 361 | 39 | 21 | Festival of Double Sunset. Great phagor crusade has been on its march for 8 years (and thus has 5 years till it reaches Oldorando). |
| 2726 | 6334 | 634 | 446 | 367 | 0 | 26 | "Embruddock" story ends (and thus Book 1 ends). Great phagor crusade reaches Oldorando. Oldorando burns. |
Column 1 displays the number of years Avernus has been operational. This is measured in Earth years (EY).
Column 2 displays the current year on Earth, by measure of the Gregorian Calendar ("Anno Domini," AD).
Column 3 displays the current year on Helliconia, as reckoned by Earth Years After Apastron (EYAA). This figure goes up to 2592, the number of small years in a Great Year (by Earth time standard), then resets to 0.
Column 4 displays the current year on Helliconia, as reckoned by Helliconian Years After Apastron (HYAA). This figure goes up to 1825, the number of small years in a Great Year (by Helliconia time standard), then resets to 0.
Column 5 displays the current year on Helliconia, as reckoned by the minds of phagors, and appears to follow the "After-Apastron" dating system (by Helliconia time standard) but is curiously off by about 80 years (the reason for this is never explicitly stated within the story). With this calendar, the small years are also called "air-turns."
Column 6 displays the current year on Helliconia, as reckoned by the common Lordly calendar, which simply counts forward from the accession of the latest local lord (by Helliconia time standard).
Column 7 displays the current year on Helliconia, as reckoned by the newly created After Union calendar, which counts forward from the year the tribes of Oldorando and Embruddock came together (by Helliconia time standard).
Column 8 displays important events occurring at the time noted.
Dave Pringle reviewed Helliconia Spring for Imagine magazine, and stated that "it seems the hour of the blockbuster has arrived and there is little we can do but submit".