Bitcoin Cash (BCH) will be undergoing a network protocol upgrade on Wednesday, May 15, 2019 at approximately 5:00 AM PT (12:00 PM UTC) via the Bitcoin ABC full node implementation. Consensus rule changes to enable Schnorr signatures and allow Segwit recovery will be activated after that time, as well as changes for replay protection for future BCH upgrades.
All Bitcoin Cash users will retain the balance of their BCH addresses, which will be persisted on the BCH blockchain. This upgrade is not considered contentious and deemed a standard blockchain upgrade.
Bittrex will close deposits and withdrawals of Bitcoin Cash on May 15, 2019 at 12:00 AM PT (7:00 PM UTC), prior to the BCH upgrade. Please send BCH deposits to Bittrex before that time to ensure that they are settled (e.g. not marked as pending). The wallet will remain closed until the hard fork block at Unix timestamp 1557921600 has passed and it is deemed safe to re-open. Trading will remain active during this time.
Bitcoin Cash 2019-MAY-15 Network Upgrade Specification: https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/2019-05-15-upgrade.md