i have 2 workbooks

workbook1 has in each sheet in cell a1 has a date of the 1st of each month
in a year. workbook2, a cell needs to look at find data in workbook1, if date
in a1 are the current month and year, day does not matter, carry out a task,
i am not sure how to look in each cell of a workbook though, please could you
advise?

thanks