Hello guys,
First of all I would like to apologize for my English mistakes, It's not my first language.
Anyways, I'm trying to use the Weka's Forecast to make a prediction of some data for the next few days. It will be like that:

@RELATION Sites
@attribute Date date 'dd/MM/yyyy'
@attribute logica2 numeric
@attribute logica1 numeric

@DATA
15/04/2017, 192, 102
15/04/2017, 194, 105
17/04/2017, 198, 108
18/04/2017, 200, 111

It is working, I can choose how many days I'll predict and which algorithm I want. However, I would like to use only one ARFF file to do more than one prediction. I want to predict more than one machine without relation between them.
For example:

@RELATION Sites
@attribute Date date 'dd/MM/yyyy'
@attribute maquina {machine1,machine2}
@attribute logica2 numeric
@attribute logica1 numeric

@DATA
15/04/2017, maq1, 192,102
15/04/2017, maq2, 194, 105
16/04/2017, maq1, 198,102
16/04/2017, maq2, 200, 105

But I'm having two problems: 1) I can't use the same Date on my Data. 2) I think The Forecast function doesn't work with non-numerical values.
My questions are: how can I deal with those problems? Is that any other software that I could use to work with a bunch of machines at the same time ? Is there any other function on Weka that I could use ??
thanks for everything!