How to display a notice if a column in a formula is blank in a calculated column

I have made a list with three column, Maintenance Cycle (with options such as Monthly, Quarterly etc), Last Maintenance Date (date picker) and Next Maintenance Date (calculated column).开发者_如何学Python

=IF([Maintenance Cycle]="Monthly",[Last Maintenance Date]+30,IF([Maintenance Cycle]="Quarterly",[Last Maintenance Date]+90,))

Not all the assets in this list will have a "Last Maintenance" column filled in so for those column it calculates from 0 + 30 days or 90 depending on the cycle. Rather than displaying "3/30/1900" in the "Next Maintenance Date" column can I get it to say "No Scheduled Maintenance" or simply be blank whenever there is nothing in the "Last Maintenance Date" column?

Thanks

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Can't you add another test in your formula?

=IF([Last Maintenance Date] = "", "No Scheduled Maintenance", [Maintenance Cycle]="Monthly",[Last Maintenance Date]+30,IF([Maintenance Cycle]="Quarterly",[Last Maintenance Date]+90,)))

Please let me know if I misunderstood your question.