From an e-mail I received:
The Kraken Website and API will be unavailable on Saturday, November 23 at 16:00 UTC (18:00 SAST) for approximately 1 hour as we perform site maintenance.
What’s the purpose of this downtime?
We’re performing a scheduled upgrade that will improve system security, as this is our top priority.
How does this affect me?
All spot exchange services including trading, funding and account access will be temporarily disabled. Margin positions will not be closed or liquidated.
How can I stay up to date on the update?
Check our status page and Twitter for updates and an announcement when the upgrade is complete.
Can I still trade futures?
Yes! If you’re signed in to your Kraken Futures account prior to the start of the upgrade, you’ll be able to trade futures without interruption. If you are a Kraken Futures client, and would like more detailed information, please go to: https://www.cryptofacilities.com/cryptocurrency-news/kraken-scheduled-downtime-november.
What happens after the upgrade is complete?
Deposits sent during the upgrade will begin to be processed in the order in which they were submitted. Withdrawals will resume shortly thereafter.
What happens after trading is enabled?
Prices and the order book may be different when compared to before the upgrade. Please note that unexpected volatility or illiquidity may exist. Consider using limit orders to avoid trades executing at unexpected prices. Margin positions will close or liquidate as they typically do. Prepare your account to be well-collateralized and/or close your positions before the upgrade to avoid unwanted liquidations caused by abrupt price changes.