Days (Keikai Spreadsheet Build 6.1.0.1 API)

java.lang.Object
- org.apache.poi.ss.formula.functions.Days

All Implemented Interfaces:

FreeRefFunction
```
public class Days
extends Object
implements FreeRefFunction
```
Calculates the number of days between two dates based on a real year, which is used in some accounting calculations.

DAYS(end_date,start_date)
- Start_date, end_date (required):
  The two dates between which you want to know the number of days.
  If start_date occurs after end_date, the DAYS function returns a negative number.
See Also:

DAYS function - Microsoft Office

- Field Summary
  
  Fields
  Modifier and Type Field Description
  
  static Days instance
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec)
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - instance
```
public static final Days instance
```
- Method Detail
  - evaluate
```
public ValueEval evaluate(ValueEval[] args,
                          OperationEvaluationContext ec)
```
    Specified by:
    
    evaluate in interface FreeRefFunction
    
    Parameters:
    
    args - the pre-evaluated arguments for this function. args is never null, nor are any of its elements.
    
    ec - primarily used to identify the source cell containing the formula being evaluated. may also be used to dynamically create reference evals.
    
    Returns:
    
    never null. Possibly an instance of ErrorEval in the case of a specified Excel error (Exceptions are never thrown to represent Excel errors).