I have a simple question: does any data gathered over time could be treated as a time series? For instance, if I measure CPU load at certain intervals, would that be a time series? Actually, I'm not interested on actual time of the measurement. I could simply mark the points along x-axis as 1, 2, 3, ... -- what is relevant to me is certain values at certain points of time.
Further, could I do time series analysis on the data set if I have irregular observation intervals?