If you're reading this page, you're using an old "Group by date" step.
Please use a "Group" step instead.
To replace a "Group by date" step
Add a "Convert timestamp to date" or "Convert text to date" step above the "Group by date" step. Choose the time interval to group by (day, week, month, quarter or year).
Add a "Group" step after the convert-to-date step. Choose the date column, and choose the desired Operation.
To give your table the exact same column names, write the column name produced by the Group Operation as "count" (if you're counting) or the input column name (if you're doing using other operation).
Delete the "Group by date" step.
To group by second, minute or hour
Follow the instructions above, but use "Timestamp math" instead of "Convert to date". Round the timestamp column down to the earliest hour, minute or second.
Why is "Group by date" deprecated?
Before deprecation, Workbench confused users who wanted to group by date. Users had to choose between "Group" (which does what they want) and "Group by date" (which might not).
In short, "Group by date" made Workbench more complex. Removing it makes Workbench simpler. Since "Group by date" was designed to radiate simplicity, the removal is apt.