Hi, 1. Can gretl recognize the ymd hms format dates automatically?
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>
2. If the data is 30 min frequency data, how to tell gretl?
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@univpm.it http://www2.econ.univpm.it/servizi/hpp/lucchetti -------------------------------------------------------