> [!IMPORTANT]
> **Key Point:** Seasonal adjustments are ideal for short events of 1--7 days. They may not work as well if you use them for extended periods (more than 14 days at a time).

Seasonality adjustments are an advanced tool that can be used to inform Smart
Bidding of expected changes in conversion rates for upcoming future events. For
more details about how seasonality adjustments work, refer to the [seasonality
adjustments help page](https://support.google.com/google-ads/answer/10369906).

Create seasonality adjustments programmatically using the
[`BiddingSeasonalityAdjustment`](https://developers.google.com/google-ads/api/reference/rpc/v26/BiddingSeasonalityAdjustment.md.txt)
resource.

## Scope

A `BiddingSeasonalityAdjustment` has a required
[`scope`](https://developers.google.com/google-ads/api/reference/rpc/v26/BiddingSeasonalityAdjustment.md.txt#scope) that can be set to
the following values. Additional scope-specific configuration options are set
according to which scope is used.

> [!NOTE]
> **Note:** There is also a read-only `CUSTOMER` scope, but it cannot be used to create new seasonality adjustments.

- `CAMPAIGN`: The adjustment is applied to specific campaigns. Set the [`campaigns`](https://developers.google.com/google-ads/api/reference/rpc/v26/BiddingSeasonalityAdjustment.md.txt#campaigns%5B%5D) field to a list of campaign resource names to which this adjustment will apply.
  - The maximum number of campaigns per `BiddingSeasonalityAdjustment` is 2,000.
- `CHANNEL`: The adjustment is applied to campaigns that belong to specific channel types. Set the [`advertising_channel_types`](https://developers.google.com/google-ads/api/reference/rpc/v26/BiddingSeasonalityAdjustment.md.txt#advertising_channel_types%5B%5D) field to a list of `AdvertisingChannelType` values to which this adjustment will apply.

## Devices

In addition to their scope, seasonality adjustments can be configured with an
optional list of device types to which the adjustment will apply. If
[`devices`](https://developers.google.com/google-ads/api/reference/rpc/v26/BiddingSeasonalityAdjustment.md.txt#devices%5B%5D) is set, the seasonality adjustment will only be
applied to traffic from the specified device types. If not specified, all device
types are included in the adjustment.

## Dates, times, and the conversion rate modifier

Aside from the scope and optional devices, each seasonality adjustment has a
[`start_date_time`](https://developers.google.com/google-ads/api/reference/rpc/v26/BiddingSeasonalityAdjustment.md.txt#start_date_time),
an [`end_date_time`](https://developers.google.com/google-ads/api/reference/rpc/v26/BiddingSeasonalityAdjustment.md.txt#end_date_time),
and a [`conversion_rate_modifier`](https://developers.google.com/google-ads/api/reference/rpc/v26/BiddingSeasonalityAdjustment.md.txt#conversion_rate_modifier).
The dates and times define the future interval that the adjustment applies to,
and the modifier is the expected conversion rate multiplier to apply. The date
and time values are in the account's timezone.

> [!NOTE]
> **Note:** The `conversion_rate_modifier` value must be between `0.1` and `10.0` and acts as a multiplier. For example, a modifier value of `1.0` means no adjustment will be applied.

## Example

The following example shows how to create a seasonality adjustment with
`CHANNEL` scope. Commented out sections demonstrate how to specify campaigns if
you were to instead set a `CAMPAIGN` scope:


### Java

```java
BiddingSeasonalityAdjustment seasonalityAdjustment =
    BiddingSeasonalityAdjustment.newBuilder()
        // A unique name is required for every seasonality adjustment.
        .setName("Seasonality adjustment #" + getPrintableDateTime())
        // The CHANNEL scope applies the conversionRateModifier to all campaigns of specific
        // advertising channel types. In this example, the conversionRateModifier will only
        // apply to Search campaigns. Use the CAMPAIGN scope to instead limit the scope to
        // specific campaigns.
        .setScope(SeasonalityEventScope.CHANNEL)
        .addAdvertisingChannelTypes(AdvertisingChannelType.SEARCH)
        // If setting scope CAMPAIGN, add individual campaign resource name(s) according to
        // the commented out line below.
        // .addCampaigns("INSERT_CAMPAIGN_RESOURCE_NAME_HERE")
        .setStartDateTime(startDateTime)
        .setEndDateTime(endDateTime)
        // The conversionRateModifier is the expected future conversion rate change. When this
        // field is unset or set to 1.0, no adjustment will be applied to traffic. The allowed
        // range is 0.1 to 10.0.
        .setConversionRateModifier(conversionRateModifier)
        .build();

BiddingSeasonalityAdjustmentOperation operation =
    BiddingSeasonalityAdjustmentOperation.newBuilder()
        .setCreate(seasonalityAdjustment)
        .build();

MutateBiddingSeasonalityAdjustmentsResponse response =
    seasonalityAdjustmentServiceClient.mutateBiddingSeasonalityAdjustments(
        customerId.toString(), ImmutableList.of(operation));
System.out.printf(
    "Added seasonality adjustment with resource name: %s%n",
    response.getResults(0).getResourceName());
      
```

### C#

```c#
BiddingSeasonalityAdjustment seasonalityAdjustment =
    new BiddingSeasonalityAdjustment()
    {
        // A unique name is required for every seasonality adjustment.
        Name = "Seasonality adjustment #" + ExampleUtilities.GetRandomString(),
        // The CHANNEL scope applies the conversionRateModifier to all campaigns of
        // specific advertising channel types. In this example, the
        // conversionRateModifier will only apply to Search campaigns. Use the
        // CAMPAIGN scope to instead limit the scope to specific campaigns.
        Scope = SeasonalityEventScope.Channel,
        AdvertisingChannelTypes = { AdvertisingChannelType.Search },
        // If setting scope CAMPAIGN, add individual campaign resource name(s)
        // according to the commented out line below.
        // Campaigns = { "INSERT_CAMPAIGN_RESOURCE_NAME_HERE" },
        // The date range should be less than 14 days.
        StartDateTime = startDateTime,
        EndDateTime = endDateTime,
        // The conversionRateModifier is the expected future conversion rate change.
        // When this field is unset or set to 1.0, no adjustment will be applied to
        // traffic. The allowed range is 0.1 to 10.0.
        ConversionRateModifier = conversionRateModifier
    };

BiddingSeasonalityAdjustmentOperation operation =
    new BiddingSeasonalityAdjustmentOperation()
    {
        Create = seasonalityAdjustment
    };

try
{
    MutateBiddingSeasonalityAdjustmentsResponse response =
        biddingSeasonalityAdjustmentService.MutateBiddingSeasonalityAdjustments(
            customerId.ToString(), new[] { operation });
    Console.WriteLine($"Added seasonality adjustment with resource name: " +
        $"{response.Results[0].ResourceName}");
}
catch (GoogleAdsException e)
{
    Console.WriteLine("Failure:");
    Console.WriteLine($"Message: {e.Message}");
    Console.WriteLine($"Failure: {e.Failure}");
    Console.WriteLine($"Request ID: {e.RequestId}");
    throw;
}
      
```

### PHP

```php
// Creates a bidding seasonality adjustment.
$seasonalityAdjustment = new BiddingSeasonalityAdjustment(
    [
    // A unique name is required for every seasonality adjustment.
    'name' => 'Seasonality adjustment #' . Helper::getPrintableDatetime(),
    // The CHANNEL scope applies the conversionRateModifier to all campaigns of specific
    // advertising channel types. In this example, the conversionRateModifier will only
    // apply to Search campaigns. Use the CAMPAIGN scope to instead limit the scope to
    // specific campaigns.
    'scope' => SeasonalityEventScope::CHANNEL,
    'advertising_channel_types' => [AdvertisingChannelType::SEARCH],
    // If setting scope CAMPAIGN, add individual campaign resource name(s) according to
    // the commented out line below.
    // 'campaigns' => ['INSERT_CAMPAIGN_RESOURCE_NAME_HERE'],
    'start_date_time' => $startDateTime,
    'end_date_time' => $endDateTime,
    // The conversionRateModifier is the expected future conversion rate change. When this
    // field is unset or set to 1.0, no adjustment will be applied to traffic. The allowed
    // range is 0.1 to 10.0.
    'conversion_rate_modifier' => $conversionRateModifier
    ]
);

// Creates a bidding seasonality adjustment operation.
$biddingSeasonalityAdjustmentOperation = new BiddingSeasonalityAdjustmentOperation();
$biddingSeasonalityAdjustmentOperation->setCreate($seasonalityAdjustment);

// Submits the bidding seasonality adjustment operation to add the bidding seasonality
// adjustment.
$biddingSeasonalityAdjustmentServiceClient =
    $googleAdsClient->getBiddingSeasonalityAdjustmentServiceClient();
$response = $biddingSeasonalityAdjustmentServiceClient->mutateBiddingSeasonalityAdjustments(
    MutateBiddingSeasonalityAdjustmentsRequest::build(
        $customerId,
        [$biddingSeasonalityAdjustmentOperation]
    )
);

printf(
    "Added seasonality adjustment with resource name: '%s'.%s",
    $response->getResults()[0]->getResourceName(),
    PHP_EOL
);
      
```

### Python

```python
bidding_seasonality_adjustment_service: (
    BiddingSeasonalityAdjustmentServiceClient
) = client.get_service("BiddingSeasonalityAdjustmentService")
operation: BiddingSeasonalityAdjustmentOperation = client.get_type(
    "BiddingSeasonalityAdjustmentOperation"
)
bidding_seasonality_adjustment: BiddingSeasonalityAdjustment = (
    operation.create
)
# A unique name is required for every seasonality adjustment.
bidding_seasonality_adjustment.name = f"Seasonality adjustment #{uuid4()}"
# The CHANNEL scope applies the conversion_rate_modifier to all campaigns of
# specific advertising channel types. In this example, the
# conversion_rate_modifier will only apply to Search campaigns. Use the
# CAMPAIGN scope to instead limit the scope to specific campaigns.
bidding_seasonality_adjustment.scope = (
    client.enums.SeasonalityEventScopeEnum.CHANNEL
)
bidding_seasonality_adjustment.advertising_channel_types.append(
    client.enums.AdvertisingChannelTypeEnum.SEARCH
)
# If setting scope CAMPAIGN, add individual campaign resource name(s)
# according to the commented out line below.
#
# bidding_seasonality_adjustment.campaigns.append(
#     "INSERT_CAMPAIGN_RESOURCE_NAME_HERE"
# )

bidding_seasonality_adjustment.start_date_time = start_date_time
bidding_seasonality_adjustment.end_date_time = end_date_time
# The conversion_rate_modifier is the expected future conversion rate
# change. When this field is unset or set to 1.0, no adjustment will be
# applied to traffic. The allowed range is 0.1 to 10.0.
bidding_seasonality_adjustment.conversion_rate_modifier = (
    conversion_rate_modifier
)

response: MutateBiddingSeasonalityAdjustmentsResponse = (
    bidding_seasonality_adjustment_service.mutate_bidding_seasonality_adjustments(
        customer_id=customer_id, operations=[operation]
    )
)

resource_name: str = response.results[0].resource_name

print(f"Added seasonality adjustment with resource name: '{resource_name}'")
      
```

### Ruby

```ruby
client = Google::Ads::GoogleAds::GoogleAdsClient.new

operation = client.operation.create_resource.bidding_seasonality_adjustment do |bsa|
  # A unique name is required for every seasonality adjustment.
  bsa.name = "Seasonality Adjustment #{(Time.new.to_f * 1000).to_i}"

  # The CHANNEL scope applies the conversion_rate_modifier to all campaigns
  # of specific advertising channel types. In this example, the
  # conversion_rate_modifier will only apply to Search campaigns. Use the
  # CAMPAIGN scope to instead limit the scope to specific campaigns.
  bsa.scope = :CHANNEL
  bsa.advertising_channel_types << :SEARCH

  # If setting scope CAMPAIGN, add individual campaign resource name(s)
  # according to the commented out line below.
  #
  # bsa.campaigns << "INSERT_CAMPAIGN_RESOURCE_NAME_HERE"

  bsa.start_date_time = start_date_time
  bsa.end_date_time = end_date_time

  # The conversion_rate_modifier is the expected future conversion rate
  # change. When this field is unset or set to 1.0, no adjustment will be
  # applied to traffic. The allowed range is 0.1 to 10.0.
  bsa.conversion_rate_modifier = conversion_rate_modifier
end

response = client.service.bidding_seasonality_adjustment.mutate_bidding_seasonality_adjustments(
  customer_id: customer_id,
  operations: [operation],
)

puts "Added seasonality adjustment with resource name #{response.results.first.resource_name}"
      
```

### Perl

```perl
my $seasonality_adjustment =
  Google::Ads::GoogleAds::V26::Resources::BiddingSeasonalityAdjustment->new({
    # A unique name is required for every seasonality adjustment.
    name => "Seasonality adjustment #" . uniqid(),
    # The CHANNEL scope applies the conversion_rate_modifier to all campaigns
    # of specific advertising channel types. In this example, the conversion_rate_modifier
    # will only apply to Search campaigns. Use the CAMPAIGN scope to instead
    # limit the scope to specific campaigns.
    scope                   => CHANNEL,
    advertisingChannelTypes => [SEARCH],
    # If setting scope CAMPAIGN, add individual campaign resource name(s)
    # according to the commented out line below.
    # campaigns     => ["INSERT_CAMPAIGN_RESOURCE_NAME_HERE"],
    startDateTime => $start_date_time,
    endDateTime   => $end_date_time,
    # The conversion_rate_modifier is the expected future conversion rate change.
    # When this field is unset or set to 1.0, no adjustment will be applied to traffic.
    # The allowed range is 0.1 to 10.0.
    conversionRateModifier => $conversion_rate_modifier
  });

my $operation =
  Google::Ads::GoogleAds::V26::Services::BiddingSeasonalityAdjustmentService::BiddingSeasonalityAdjustmentOperation
  ->new({
    create => $seasonality_adjustment
  });

my $response = $api_client->BiddingSeasonalityAdjustmentService()->mutate({
    customerId => $customer_id,
    operations => [$operation]});

printf "Added seasonality adjustment with resource name: '%s'.\n",
  $response->{results}[0]{resourceName};
      
```

### curl

> [!NOTE]
> **Note:** While a direct REST code sample for this step isn't provided here, you can achieve this using a manual REST request.   
>
> Refer to the Google Ads API REST interface documentation and the method-specific reference pages. You will need to construct the JSON payload based on the proto definitions.   
>
> Key Resources:
>
> - [Using REST](https://developers.google.com/google-ads/api/rest/overview.md.txt)
> - [REST Interface Structure](https://developers.google.com/google-ads/api/rest/design/overview.md.txt)
> - [JSON Field Mappings](https://developers.google.com/google-ads/api/rest/design/json-mappings.md.txt)
> - Consult the [REST API Reference](https://developers.google.com/google-ads/api/reference/rpc/latest/overview) for the specific service and method.

<br />