The IRS issues most refunds in about 21 days, although some returns take more time to review. Unfortunately, it seems alot of customers are experiencing this long delay for refunds. Turbotax gives an estimated date based on the IRS's 21 day timeframe. So it all depends on the IRS and how fast your tax return moves along in the system. TurboTax does not receive any updates from the IRS.
If your return on the IRS Where’s My Federal Refund? site shows it is processing,
during processing, the government reviews your refund. During the review process, they look for math errors on your return (extremely rare in TurboTax) and they also check if you owe back taxes, unpaid child support, or other debts.
If they need to make any corrections, they may offset (reduce) your refund. In some cases, the correction might even increase your refund.
Once that part's done, the government approves your refund, which means it's ready to be deposited or sent. At that point the IRS site will update with a direct deposit date.
Please see the links below for more information: