[Gretl-users] Problem isoweek() for week 53

Hi all, I've found a rather strange 'result' when using the isoweek() function. For some reason the last 2 days of calendar year 2019 do not refer to week 53 but week 52 instead. For 2020, however, things are alright. Do I miss anything or is this a kind of bug? Best, Artur <hansl> clear nulldata 800 setobs 7 2019-01-01 --time-series series year, month, day isoconv($obsdate, &year, &month, &day) series week = isoweek(year, month, day)               # new week starts Monday smpl month == 12 && day > 28 --restrict print year month day week -o </hansl> returns <output>           year        month          day         week 1         2019           12           29           52 2         2019           12           30            1            # WEIRD 3         2019           12           31            1            # WEIRD 4         2020           12           29           53 5         2020           12           30           53 6         2020           12           31           53 </output>