Just received this email.
Between 10:00 am CST (2/29) / 4:00 pm UTC (2/29) / 1:00 am KST (3/1) and 1:00 pm CST (2/29) / 7:00 pm UTC (2/29) / 4:00 am KST (3/1), we will be automatically updating your Hub to the latest firmware. The update is expected to take less than 10 minutes, during which time your Hub will temporarily go offline. The firmware update includes video enhancements, new security options, and bug fixes. This update only affects Samsung SmartThings Hubs (Hub v2).