On 06/03/2026 06:30, Ramki S wrote: It depends on what you mean by "automatically": gretl has several functions for manipulating calendar dates. Chapter 19 of the User's Guide is devoted to this. For example, if you read a csv file that looks like this: datestr,x "2025-04-06 12:00:00",22 "2025-04-06 12:30:00",24 "2025-04-06 13:00:00",45 "2025-04-06 13:30:00",NA "2025-04-06 14:00:00",16 gretl will read column 1 as a string. You can convert it into the "Unix seconds" format using the function "strptime", as in <hansl> series ut = strptime(datestr, "%Y-%m-%d %H:%M:%S") </hansl> If you consider the day as the "larger" time unit, than you have 24 subperiods in a period and all you need to do is <hansl> setobs 24 1:1 --special-time-series </hansl> You can achieve the same effect via the GUI: go to the "Data" menu and choose "Dataset structure". ------------------------------------------------------- Riccardo (Jack) Lucchetti Dipartimento di Scienze Economiche e Sociali (DiSES) Università Politecnica delle Marche (formerly known as Università di Ancona) r.lucchetti(a)univpm.it http://www2.econ.univpm.it/servizi/hpp/lucchetti -------------------------------------------------------