Unfortunately for now there is no way to tell, however it should be for sure. It is planned to be somewhere in the player info screen, but as you can see there is no such screen at this moment.
As for the truce - when you use truce item, it will not start immediately, it is prepared and will be active in 12 hours, so when you activate it, there is a small white flag that indicated that truce is activated, but not actually active yet, hence the (correct) hint about when it starts. When the initial 12 hours elapsed then the actual truce starts and there is another 12 hours of truce and the white flag is big this time.
This activation delay serves 2 purposes:
1. People will not cast truce suddenly when they see big scary army marching in front of your door - that will be unfair towards the attacking player and will be very frsutating.
2. People will not be able to cast endlessly. This truce thing is made for people to sleep well at night, if they cast it in advance, not to gain total invulnerability :)
P.S. yes, this conversation probable belongs to somewhere else. Probably a thread in Totem Tribe 2 general section since this is not a bug. I can move it, but I will leave it to buckwheat so she could practice the moderator tools :)
