# Date math

### Description
Performs date arithmetic on matching objects

### Input
- `A [OBJ,DATE]`: a list of pairs
- `B [OBJ,INT]`: a list of pairs

### Output
- `RESULT [OBJ,DATE]`: result of the operation

### Parameters
- `Expression`: the mathematical expression to compute
  - use `$A` and `$B` to refer to the values comings from inputs `A` and `B`
  - arithmetic operators `+` and `-`
  - the expression is evaluated by the database engine. See [MonetDB Functions and Operators](https://www.monetdb.org/Documentation/SQLReference/FunctionsAndOperators/MathematicalFunctionsOperators) for a full list of functions and operators available.
- `Unit`: how to interpret the integer value in `B` (days, seconds, ..)