Longevity of dairy cattle is an important trait from an economic and welfare perspective. Dairy cows are culled for various reasons and therefore the trait definition of longevity might have changed over time. Also, culling is likely to be affected by the end of the quota year, and therefore a seasonal effect is expected. Therefore the objective was to evaluate if longevity is a different trait between years or seasons of first calving, utilizing genetic links through common bulls. Survival was defined as survival until 12 mo after first calving. The data set comprised 524,529 animals that could have lived until 12 mo after the first calving, with the first calving between 1988 and 2011. Multiple trait models were used with survival defined in 3 8-year blocks (1988–1995, 1996–2003, and 2004–2011) or 4 seasons of first calving (Jan-Mar, Apr-Jun, Jul-Sep, and Oct-Dec). The mean survival was 87.8% in the total data set, but increased with more recent calving years. The lowest survival rate was in 1991 with 82.9% surviving the first 12 mo and highest survival rate was in 2007 (92.2%). Survival rate also varied between calving months, with highest survival rate in September with 89.2% and lowest survival rate in March with 86.3%. Age of first calving showed an optimum for survival for heifers calved between 22 and 26 mo of age, with survival rates of 88.4% or higher. Survival rate decreases 0.75% for each extra month calving after 26 mo. Genetic correlations between 1988 and 1995 and 2004–200 was lowest (0.67 ± 0.15), and suggests survival has changed over years. Genetic correlations between all seasons were higher than 0.90, and although there appears a phenotypic effect of the end of the quota year on survival, genetically there is no effect of season of calving on survival until 12 mo after first calving.