# Use client-side timestamps in queries in Amazon Keyspaces
<a name="client-side-timestamps-how-to-queries"></a>

After you have turned on client-side timestamps, you can pass the timestamp in your `INSERT`, `UPDATE`, and `DELETE` statements with the `USING TIMESTAMP` clause. 

The timestamp value is a `bigint` representing a number of microseconds since the standard base time known as the epoch: January 1 1970 at 00:00:00 GMT. A timestamp that is supplied by the client has to fall between the range of 2 days in the past and 5 minutes in the future from the current wall clock time.

Amazon Keyspaces keeps timestamp metadata for the life of the data. You can use the `WRITETIME` function to look up timestamps that occurred years in the past. For more information about CQL syntax, see [DML statements (data manipulation language) in Amazon Keyspaces](cql.dml.md).

The following CQL statement is an example of how to use a timestamp as an `update_parameter`. 

```
INSERT INTO {{catalog.book_awards}} (year, award, rank, category, book_title, author, publisher)
   VALUES (2022, 'Wolf', 4, 'Non-Fiction', 'Science Update', 'Ana Carolina Silva', 'SomePublisher') 
   USING TIMESTAMP 1669069624;
```

If you do not specify a timestamp in your CQL query, Amazon Keyspaces uses the timestamp passed by your client driver. If no timestamp is supplied by the client driver, Amazon Keyspaces assigns a server-side timestamp for your write operation. 

To see the timestamp value that is stored for a specific column, you can use the `WRITETIME` function in a `SELECT` statement as shown in the following example. 

```
SELECT year, award, rank, category, book_title, author, publisher, WRITETIME(year), WRITETIME(award), WRITETIME(rank),
  WRITETIME(category), WRITETIME(book_title), WRITETIME(author), WRITETIME(publisher) from catalog.book_awards;
```