Sum of amounts by non-sequential date

I’m sure this probably very simple but I’m tying myself in knots with this…

I have two columns, one is dates and the other amounts. I want to add the amounts by date on a day by day basis with the result in two columns elsewhere - date next to the sum of the amounts for that date, in date order.
. The only problem is that the dates in the source table are not sequential so e.g 04/02/17, 05/02/17/, 07/02/17, 04/02/17, 06/02/17, 04/02/17, 06/02/17, 05/02/17 etc etc.

All help gratefully received


→insert→Pivottable -or- →Data→Pivottable→create… (depends on your LO-version )

… drag “Dates” to Rowfield, drag “Amount” to DataField … click ok!