Updated: it's 18 months.
I think they got the wrong promo period: must be 18 months. I just got an email, copy/paste:
Start saving today by transferring a balance. With your Total Rewards® Visa® Card, you'll get a 0% promotional APR and no fee on Balance Transfers through June 2019. After June 2019, you will be charged a variable rate of 19.74% APR based on the Prime Rate. At that rate, you can make any high-interest balances a thing of the past.
TOTAL REWARDS® VISA® CARD PROMOTIONAL BALANCE TRANSFER OFFER INFORMATION
Promotional Interest and Fee Information:
• 0% promotional APR through June 2019. After June 2019, for this Balance Transfer offer, you will be charged a variable APR of 19.74% based on the Prime Rate. This rate will vary with the market based on the Prime Rate.
• You must use this offer by March 31, 2018 for the promotional APR to apply. If you attempt to use the offer after this date, we will not honor your request.
• There are no fees for Balance Transfers associated with this promotional offer. See your Credit Card Agreement for fees that apply to Balance Transfers outside of this promotional offer.
Important Balance Transfer Information:
• The promotional APR applies only to balances transferred in connection with this offer.
• The promotional APR does not apply to any existing balances on your account.
• You cannot transfer balances from any other account you have with Comenity Bank or Comenity Capital Bank.
• Transferred balance amounts do not qualify for Reward Credits.
• We may process your requests in any order we choose.
• If your request(s) exceed the available credit on your account, we may decline to process the request or transfer a lesser amount than requested.
• The cash limit is 20% of the account available credit limit. The available cash on your account will be reduced by the total amount of the Balance Transfer(s).
• We reserve the right not to process Balance Transfer requests for any reason.
• Not all accounts will be eligible for Balance Transfers.
• It may take up to 30 days to complete your requested transfer(s). You should continue to make payments on any account from which you are transferring balances until the balance transfer appears on the other account as a credit. We will cancel the request if it is not completed within 30 days. Subject to credit approval.
*As a result of recent payments and charges, your account balance may have changed. Please call our automated phone system 24 hours a day at 1-855-497-8153 (TDD/TTY 1-800-695-1788) or go to Comenity.net/TotalRewardsVisa to access your available credit or other important account information.
The Total Rewards® Visa® and Total Rewards® Visa Signature® Cards are issued by Comenity Bank pursuant to a license from Visa USA Inc. VISA is a registered trademark of Visa International Service Association and used under license.
Caesars Total Rewards brand and its related marks are owned by Caesars Entertainment Operating Company, Inc. Used with permission.
Must be 21 or older to gamble. (Must be 19 or older in Ontario). Know When To Stop Before You Start.® Gambling Problem? Call 1-800-522-4700. (IL, PA, NJ or CA: If you or someone you know has a gambling problem, crisis counseling and referral services can be accessed by calling 1-800-GAMBLER (1-800-426- 2537). MO: 1-888-BETSOFF. IA: 1-800-BETSOFF. IN: 1-800-9WITHIT. MD: Please play responsibly, for help visit mdgamblinghelp.org or call 1-800-GAMBLER. Ontario: PlaySmart 1-888-230-3505.) ©2017, Caesars License Company, LLC.