Hi,
You probably mean "Mass update" ?
Assuming you using CL_GUI_ALV_GRID and it is residing within CL_GUI_CUSTOM_CONTAINER .
Add a new field to the screen type date .
Add a new button in the status "Mass update"
If the user use "Mass update" just update the INTERNAL table (ABAP Keyword Documentation ).
Since at PBO CALL METHOD CL_GUI_ALV_GRID->refresh_table_display will occur the date field for all line should be filled .
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Regards.