I have tested the code I found in https://www.b4x.com/android/forum/threads/opening-default-clock-alarm-app.26437/#content and I have found that it works fine on Samsung but I think not Works on HTC.
Android.content.ActivityNotFoundException: No activity found to handle Intent {act = android.intent.action.SET_ALARM flg = 0x20000 (has extras)}
Android.content.ActivityNotFoundException: No activity found to handle Intent {act = android.intent.action.SET_ALARM flg = 0x20000 (has extras)}