The Gold Pass is valid for one month from the day you subscribe or from when the automatic renewal takes place.
Benefits from a Gold Pass (200cc, ability to receive additional tour gifts, etc.) that are outside the one-month validity period will remain valid until the daily reset (6:00 AM UTC, or 11:00 PM PDT/10:00 PM PST) following expiration.
You can start to use the Gold Pass once you have subscribed.
You can check when the validity period ends on the subscription status screen of your device's operating system.
How can I check my subscription status?