Grouping dates

Hello I am new to knime and I try to group dates by months and years in an excell sheet. Although i use the string to date time node and the group by node i can not managed it. Please if you have any idea.

Hi John,

after you have converted your string dates to date/time, you can use the Date Field Extractor node to create two working columns with months and years respectively, extracted from those date/times, then use a GroupBy node to group on them as needed.

You can use the aggregate options in the GroupBy node to aggregate the other columns, which basically results in a pivot table like you would do in Excel.

Let me know if you need an example workflow, but with the indications above I think you will be able to create a proper one by yourself.

Good KNIME learning!


one of the problems encountered is that while the excel file has two columns with dates in when i use the string to date node i see:  No String compatible column found

When you read in the XLS file with the XLS Reader node, did you check the column types for your original date columns? They should be String, otherwise the String to Date Time node can't work on them.


Hello John,

can you provide a workflow that shows this problem?