RT info:eu-repo/semantics/article T1 Seasonal variations in daily data: An application to air passenger arrivals A1 Cáceres Hernández, José Juan A1 Martín Rodríguez, Carmen Gloria A2 Economía Aplicada y Métodos Cuantitativos K1 Daily data K1 Seasonal variations K1 Splines K1 Air passenger arrivals AB The aim of this paper is to describe and compare seasonal effects in daily air passenger arrivals. Multiple seasonal cycles of different lengths are usually observed in daily time series. To model weekly cycles over a short and fixed seasonal period, conventional formulations can be applied. However, the length of yearly and, above all, monthly seasonal cycles is not fixed. Yet, whatever the lengths of the seasonal periods, seasonal cycles can be modelled by using evolving spline functions in such a way that a seasonal effect at a proportion of the seasonal period is defined as a non-fixed parametric formulation of this proportion. Thus, restricted evolving spline models are useful to model this type of seasonal variation. The areas under the splines can measure changes in the magnitude of seasonal variations over time and can be used to compare the relevance of seasonal variations for different seasonal periods or different time series. This proposal is illustrated by applying it to daily series of air passengers arriving in the Canary Islands and at the rest of Spain's airports. SN 0969-6997 YR 2023 FD 2023 LK http://riull.ull.es/xmlui/handle/915/39624 UL http://riull.ull.es/xmlui/handle/915/39624 LA en DS Repositorio institucional de la Universidad de La Laguna RD 05-ene-2025