I have a WS monitoring use of water on a daily basis. In column A i have the
dates for a whole year, in column B I put in the amount of liters passed the
measuring device and in column C i have a formula that gives the amount of
water used since last reading. (Simply latest value - previous value)

My problem occurs when there comes a day when the counter has not been
checked and there is no input value. I Want to ceep all dates in Column A

How can I solve this?