Thanks Phil, it is exactly what I was looking for. David, I took into account how to make valid math operations, so I understand your concern about it. I will definitely change all my scripts and functions to considered the time as character, but as I need a clear output soon (deadline is close) I do not have the time now to go through all of them. But thanks again for your useful comment.
There is still a remaining issue. If I do the following: test=zoo(myseries,format(strptime(sprintf('%06d',breaks),'%H%M%S'),'%H:%M')) plot(test) it does not work, as it says the following error (sorry for the Italian words) Errore in plot.window(...) : i valori 'xlim' devono essere finiti Inoltre: Warning messages: 1: In xy.coords(x, y, xlabel, ylabel, log) : si รจ prodotto un NA per coercizione 2: In min(x) : no non-missing arguments to min; returning Inf 3: In max(x) : no non-missing arguments to max; returning -Inf Thanks again for your help. -- View this message in context: http://r.789695.n4.nabble.com/Chron-object-in-time-series-plot-tp3002285p3002553.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.