Hi subrahmaniam,
Per understanding, if you want to do all in your application, you need to develop according to NTP protocol (i.e. RFC-1305, RFC-5905).
In latest Legato release, le_data_GetDate() and le_data_GetTime() is introduced for NTP support to ease development.
https://docs.legato.io/latest/c_le_data.html#c_le_data_time
But for your case using 16.07, I think the easiest way is to use Linux script or call those Linux tool in your app.
You may refer to my test below:
root@swi-mdm9x15:~# cm data connect 30&
root@swi-mdm9x15:~# Connected through interface ‘rmnet0’root@swi-mdm9x15:~# ntpd -p pool.ntp.org
root@swi-mdm9x15:~# date
Fri Jul 13 09:50:43 UTC 2018
root@swi-mdm9x15:~# cm rtc set “$(date +‘%d %b %Y %H:%M:%S’)”
root@swi-mdm9x15:~# cm rtc
13 Jul 2018 09:50:58
root@swi-mdm9x15:~#
Hope it help.
Thx