@JAnd : That would probably be the easiest solution, plus you would get the added benefit of the new Time Series commands (something like SeasonalSubseriesPlot might of interest).
That said, you could also create your own procedure to deal with your 'time series'. To do this, I would first suggest that you could store your 'time series' in whatever storage container you'd like. A matrix is probably the easiest to work with here, and ff you use ImportMatrix (or ExcelTools given that you have an older version of Maple) to get your data, you could just leave the data in the default 'Matrix' that it comes in to.
MyData := ImportMatrix("PathToMyData") or
MyData := ExcelTools:-Import("PathToMyData")
Next you'll need to do some work to grab rows and columns. For example, to return the first row of months, you would just use MyData[ 1 , 1 .. () ]. For you to create your own Time series plot, you'll need to work with the data in this way.
Something like this might help to generate 'time series' plots:
TimePlotter := proc (dataset)
return Statistics:-LineChart(convert(dataset[2 .. (), 2 ..()]^%T, listlist),
'tickmarks' = [[seq(i = typeset(dataset[i, 1]),
i = 2 .. LinearAlgebra:-RowDimension(dataset))], default],
'legend' = [ seq(dataset[1, i], i = 2 .. LinearAlgebra:-ColumnDimension(dataset) ) ],
'gridlines' = true,
'symbolsize' = 1,
'symbol' = 'solidcircle',
'thickness' = 3 )
TimePlotter(MyData[ .. , [ 1 , #Column ] ] ) for just one column of data.
Here I needed to do some tricks to keep track of the dates and column headings such that we can use these for tickmarks and legend entries. Also, since only the first row and column contain non-numeric entires, we limit the data for the LineChart plot to rows and columns 2 and above.