如果是新装的ise2.7，没有打任何patch包的话，确实是存在这个问题的。需要更新ise patch1才可以进行更改。
-----
isetest/admin# sh ver
Cisco Application Deployment Engine OS Release: 2.7
ADE-OS Build Version: 2.7.0.901.6
ADE-OS System Architecture: x86_64
Copyright (c) 2005-2019 by Cisco Systems, Inc.
All rights reserved.
Hostname: isetest
Version information of installed applications
---------------------------------------------
Cisco Identity Services Engine
---------------------------------------------
Version : 2.7.0.356
Build Date : Thu Nov 14 10:21:59 2019
Install Date : Thu Mar 2 13:13:46 2023
Cisco Identity Services Engine Patch
---------------------------------------------
Version : 1
Install Date : Thu Mar 02 14:11:19 2023
isetest/admin#
isetest/admin(config)# clock timezone Etc/GMT+8
% On ise distributed deployments, it is recommended all nodes be
% configured with the same time zone.
% Changing the time zone may result in undesired side effects
% Recommended to reimage the node after changing the time zone
Are you sure you want to proceed with time zone change? Y/N [N]: y
System timezone was modified. You must restart ISE for change to take effect.
Do you want to restart ISE now? (yes/no) no
isetest/admin(config)# clock timezone Asia/Shanghai
% On ise distributed deployments, it is recommended all nodes be
% configured with the same time zone.
% Changing the time zone may result in undesired side effects
% Recommended to reimage the node after changing the time zone
Are you sure you want to proceed with time zone change? Y/N [N]: y
System timezone was modified. You must restart ISE for change to take effect.
Do you want to restart ISE now? (yes/no) yes //根据实际需要选择是否立即重启ise
Stopping ISE Monitoring & Troubleshooting Log Processor...
PassiveID WMI Service is disabled
PassiveID Syslog Service is disabled
PassiveID API Service is disabled
PassiveID Agent Service is disabled
PassiveID Endpoint Service is disabled
PassiveID SPAN Service is disabled
ISE pxGrid processes are disabled
Stopping ISE Application Server...
Stopping ISE Certificate Authority Service...
Stopping ISE EST Service...
ISE Sxp Engine Service is disabled
Stopping TC-NAC Service ...
VA Service is not running
ISE VA Database is not running
Error: No such container: wifisetup-container
wifisetup-container is not running
Segmentation Policy Service is disabled
Stopping ISE Messaging Service...
Stopping docker daemon...
Stopping ISE Profiler Database...
Stopping ISE Indexing Engine...
Stopping ISE Monitoring & Troubleshooting Session Database...
Stopping ISE AD Connector...
Stopping ISE Database processes...
ISE Database processes already running, PID: 14014
Stopping ISE Database processes...
Starting docker daemon ...
Starting ISE Messaging Service...
Service 'stunnel' -- doesn't exist
Starting ISE Monitoring & Troubleshooting Session Database...
Starting ISE Profiler Database...
Starting ISE Application Server...
Starting ISE Monitoring & Troubleshooting Log Processor...
Starting ISE Indexing Engine...
WifiSetup is disabled.....
Starting ISE Certificate Authority Service...
NSS database for CA Service is ready
Starting ISE AD Connector...
Starting ISE EST Service...
Note: ISE Processes are initializing. Use 'show application status ise'
CLI to verify all processes are in running state.
isetest/admin(config)#
show timezones 可以查看可配置的时区，如果时区写的不对的话，会提示Invalid timezone
-----
如果有可用的ntp配置的话，也可以不修改timezone设置，保持默认UTC，web访问的时候应该会自动判断当前的时区。
参考：https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvo49755
