#To get time and ntp info for  all esxi :

Get-VMHost | Sort Name | Select Name,  @{N="NTPServer";E={$_ |Get-VMHostNtpServer}},   Timezone,  @{N="CurrentTime";E={(Get-View $_.ExtensionData.ConfigManager.DateTimeSystem) | Foreach {$_.QueryDateTime().ToLocalTime()}}},  @{N="ServiceRunning";E={(Get-VmHostService -VMHost $_ |Where-Object {$_.key-eq "ntpd"}).Running}} ` | Format-Table -AutoSize

or 

Get-VMHost | Get-VMHostService | Where-Object {$_.key -eq "ntpd"} | select vmhost, label, Key, Policy, Running, Required |format-table -autosize

# Remove wrong NTP Server and Add correct NTP server

Get-VMHost | Remove-VMHostNtpServer -NtpServer ntp.mn Confirm:$false
Get-VMHost | Add-VMHostNtpServer -NtpServer 0.asia.pool.ntp.org

# Start NTP Service and set to Automatic

Get-VMHost | Get-VMHostService | Where-Object {$_.key -eq "ntpd" } | Start-VMHostService
Get-VMHost | Get-VMHostService | Where-Object {$_.key -eq "ntpd" } | Set-VMHostService -policy "automatic"