---
title: set_integer_now_func() | Tiger Data Docs
description: Define the relationship between integer time values and actual time
---

Since [1.5.0](https://github.com/timescale/timescaledb/releases/tag/1.5.0)

Override the [`now()`](https://www.postgresql.org/docs/16/functions-datetime.html) date/time function used to set the current time in the integer `time` column in a hypertable. Many policies only apply to [chunks](/docs/learn/hypertables/understand-hypertables/index.md) of a certain age. `integer_now_func` determines the age of each chunk.

The function you set as `integer_now_func` has no arguments. It must be either:

- `IMMUTABLE`: Use when you execute the query each time rather than prepare it prior to execution. The value for `integer_now_func` is computed before the plan is generated. This generates a significantly smaller plan, especially if you have a lot of chunks.

- `STABLE`: `integer_now_func` is evaluated just before query execution starts. [chunk pruning](https://www.timescale.com/blog/optimizing-queries-timescaledb-hypertables-with-partitions-postgresql-6366873a995d) is executed at runtime. This generates a correct result, but may increase planning time.

`set_integer_now_func` does not work on tables where the `time` column type is `TIMESTAMP`, `TIMESTAMPTZ`, or `DATE`.

## Samples

Set the integer `now` function for a hypertable with a time column in [unix time](https://en.wikipedia.org/wiki/Unix_time).

- `IMMUTABLE`: when you execute the query each time:

  ```
  CREATE OR REPLACE FUNCTION unix_now_immutable() returns BIGINT LANGUAGE SQL IMMUTABLE as $$  SELECT extract (epoch from now())::BIGINT $$;


  SELECT set_integer_now_func('hypertable_name', 'unix_now_immutable');
  ```

- `STABLE`: for prepared statements:

  ```
  CREATE OR REPLACE FUNCTION unix_now_stable() returns BIGINT LANGUAGE SQL STABLE AS $$ SELECT extract(epoch from now())::BIGINT $$;


  SELECT set_integer_now_func('hypertable_name', 'unix_now_stable');
  ```

## Arguments

The syntax is:

```
SELECT set_integer_now_func(
    hypertable = '<hypertable_name>',
    integer_now_func = '<function_name>',
    replace_if_exists = true | false
);
```

| Name                | Type     | Default | Required | Description                                                                                      |
| ------------------- | -------- | ------- | -------- | ------------------------------------------------------------------------------------------------ |
| `hypertable`        | REGCLASS | -       | ✔        | The hypertable `integer_now_func` is used in.                                                    |
| `integer_now_func`  | REGPROC  | -       | ✔        | A function that returns the current time set in each row in the `time` column in the hypertable. |
| `replace_if_exists` | BOOLEAN  | `FALSE` | ✖        | Set to `true` to override `integer_now_func` when you have previously set a custom function.     |

## Returns

This function returns void.