DateDiffExpression (Morphia)

java.lang.Object
- dev.morphia.aggregation.expressions.impls.Expression
- - dev.morphia.aggregation.expressions.impls.DateDiffExpression

```
public class DateDiffExpression
extends Expression
```
Returns the difference between two dates.

Since:

2.3

Since server release
5.0

Constructor Summary

Constructors
Constructor Description

DateDiffExpression(Expression startDate, Expression endDate, TimeUnit unit)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`encode(Datastore datastore, BsonWriter writer, EncoderContext encoderContext)`
`DateDiffExpression`	`startOfWeek(DayOfWeek startOfWeek)`	The start of the week.
`DateDiffExpression`	`timezone(Expression timezone)`	The timezone to carry out the operation.

Methods inherited from class dev.morphia.aggregation.expressions.impls.Expression
getOperation, getValue, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - DateDiffExpression
```
public DateDiffExpression(Expression startDate,
                          Expression endDate,
                          TimeUnit unit)
```
- Method Detail
  - encode
```
public void encode(Datastore datastore,
                   BsonWriter writer,
                   EncoderContext encoderContext)
```
    Overrides:
    
    encode in class Expression
    
    Parameters:
    
    datastore - the datastore
    
    writer - the writer
    
    encoderContext - the context
  - startOfWeek
```
public DateDiffExpression startOfWeek(DayOfWeek startOfWeek)
```
    The start of the week. Used when unit is week. Defaults to Sunday.
    
    Parameters:
    
    startOfWeek - the start of the week
    
    Returns:
    
    this
  - timezone
```
public DateDiffExpression timezone(Expression timezone)
```
    The timezone to carry out the operation. must be a valid expression that resolves to a string formatted as either an Olson Timezone Identifier or a UTC Offset. If no timezone is provided, the result is displayed in UTC.
    
    Parameters:
    
    timezone - the timezone expression
    
    Since:
    
    2.3