@carljr from the manual
Silent Mode
You can silence the ringers on the base and all handsets for a specific period of time.
1. With the phone in standby, press and hold # on any handset. The phone prompts you to select the number of hours (1 - 9 or Always On) that you want it to stay in silent mode.
2. To confirm, press # or just wait about 5 seconds. The phone turns on the answering system and displays Silent Mode On on each handset.
3. After the selected number of hours, the phone automatically exits silent mode. To exit silent mode manually, press and hold # again.
You can download teh manual [https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjk6-qL0sbWAhUGKCYKHSuXB8IQFggoMAA&url=https%3A%2F%2Fwww.101phones.com%2Fcontent%2Fpdf%2Funiden%2FD1760.pdf&usg=AFQjCNGyEKqIzmjqWFrsuIA4L_fpOvLOxg|from here]