Here's how to configure the SPA1xx time zone in an XML configuration file:
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<router-configuration>
<Time_Setup>
<Time_Zone>-06 2 1</Time_Zone>
<Auto_Adjust_Clock>1</Auto_Adjust_Clock>
<Time_Server_Mode>manual</Time_Server_Mode>
<Time_Server>0.pool.ntp.org</Time_Server>
<Resync_Timer>60</Resync_Timer>
<Auto_Recovery_System_Time>1</Auto_Recovery_System_Time>
<Time_Mode>1</Time_Mode>
</Time_Setup>
</router-configuration>
</flat-profile>
The Time_Zone parameters and code representing the time zone are listed in attached document.
<end>