Timing is essential in seasonally changing habitats. Survival and reproduction are enhanced through precise adjustment to environmental conditions. Avian seasonal behaviour, that is, diverse activities associated with reproduction, moult and migration, has an endogenous basis and is ultimately linked to changes in environmental factors such as food supply. However, behaviour occurs in social contexts, and interactions with conspecifics are intimately linked to seasonal activities. Time programmes set the stage for social behaviour, which in turn fine-tunes seasonal activities. We propose that avian schedules are genuinely ‘sociable’: birds communicate seasonal behaviour by both intentional and inadvertent information transfer and negotiate it in competitive and cooperative interactions. Studying the interplay between seasonal and social behaviour can add to our understanding of animal behaviour, including mechanisms by which birds could cope with changing environmental conditions.