File: app/code/local/Thiagoprz/Birthdaycoupon/etc/config.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Thiagoprz_Birthdaycoupon>
            <version>0.0.1</version>
        </Thiagoprz_Birthdaycoupon>
    </modules>
    <global>
        <helpers>
            <thiagoprz_birthdaycoupon>
                <class>thiagoprz_birthdaycoupon_Helper</class>
            </thiagoprz_birthdaycoupon>
        </helpers>
        <models>
            <thiagoprz_birthdaycoupon>
                <class>Thiagoprz_Birthdaycoupon_Model</class>
            </thiagoprz_birthdaycoupon>
        </models>
    </global>
    <adminhtml>
        <events>
            <salesrule_rule_condition_combine>
                <observers>
                    <thiagoprz_birthdaycoupon_salesrule_rule_condition_combine>
                        <type>model</type>
                        <class>Thiagoprz_Birthdaycoupon_Model_Observer</class>
                        <method>addBirthdayCondition</method>
                    </thiagoprz_birthdaycoupon_salesrule_rule_condition_combine>
                </observers>
            </salesrule_rule_condition_combine>
        </events>
    </adminhtml>
</config>