One of the most important phases in planning a vacation is the booking activity process. The aim of this research is to study if the country of origin and/or seasonality has a link with the booking period (BP). The data used is from the largest booking platform of self-catering accommodations in the region of the Romand Valais in Switzerland. The data set contains more than 141,000 transactions from 1st January 2010 to 26 December 2016. This research uses the Kaplan-Meier (KM) survival method for modelling the length of BP after the resampling process. Seasonality of travel shows a higher discrimination level on BP than country of origin. This demonstrates that the importance of socio-demographical factors have been over-estimated against other factors such as travel motivations that may include external constraints such as school holiday timing. For practitioners, the results shed some light on planning behaviour across different markets and seasons. For scholars, beside methodological issues, the results show that countries of origin are less relevant than seasonality in the characterisation of the planning vacation process (PVP).