Hi there, I really like the time series object from scipy but I have a problem with manipulating dates. Here is a copy from my ipython session: ----------------------------------------------------------------------------- In [748]: myts=ts.time_series(data=n.arange(20).reshape(2,10).T, dates=n.arange(10)+720000, freq='D') In [749]: myts Out[749]: timeseries( [[ 0 10] [ 1 11] [ 2 12] [ 3 13] [ 4 14] [ 5 15] [ 6 16] [ 7 17] [ 8 18] [ 9 19]], dates = [17-Apr-1972 ... 26-Apr-1972], freq = D) In [750]: myts.dates[myts.weekday==1]+=1 In [751]: myts.dates Out[751]: DateArray([17-Apr-1972, 19-Apr-1972, 19-Apr-1972, 20-Apr-1972, 21-Apr-1972, 22-Apr-1972, 23-Apr-1972, 24-Apr-1972, 26-Apr-1972, 26-Apr-1972], freq='D') In [752]: myts.has_duplicated_dates() Out[752]: False ----------------------------------------------------------------------------- In words: I can change the dates by hand (in line 750), but the object is not aware of it, i.e. it still thinks that it does not contain any duplicates but the dates were however affected by the manipulation in line 750, cf. line 751. Is there a work-around? all the best. Cheers, Georges