Hello & Welcome to Just Answer,
I'm Greg and will do my best to assist you today.
Sorry to hear of any issue you are having with your phones.
To help you with this issue, may I ask:
1) The FULL Model Number of the phone system you are working with? If this is a cordless system, that model should be printed on a sticker on the bottom or back of the MAIN base.
I see it has been a few days and I haven't seen a response on this page, so I just wanted to follow up to see if you have any more questions concerning this issue OR if the issue was resolved?
I only ask because I'm pretty sure I can guide you through setting the time - once I know the model of your system.
I look forward to any further questions or results that you may have.
Thanks, ***** *****--. .-(im)