You could use the debug again to show when trigger will send. It's not a count down but will give you a time.
[{"id":"564c0344.615fe4","type":"inject","z":"6524ce52.cafd2","name":"","props":[{"p":"reset","v":"true","vt":"bool"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"30 17 * * *","once":false,"onceDelay":0.1,"topic":"","payloadType":"str","x":150.00001525878906,"y":1063.9999389648438,"wires":[["7e9720ad.01208","c3724858.a919d8","20a26fcd.f2d89"]]},{"id":"7e9720ad.01208","type":"trigger","z":"6524ce52.cafd2","name":"","op1":"","op2":"","op1type":"pay","op2type":"payl","duration":"180","extend":true,"units":"min","reset":"","bytopic":"all","topic":"topic","outputs":1,"x":410,"y":1120,"wires":[["ddcb339c.d115b"]]},{"id":"c3724858.a919d8","type":"debug","z":"6524ce52.cafd2","name":"","active":false,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","statusVal":"$moment().format(\"ddd HH:mm:ss\")\t\t\t","statusType":"jsonata","x":320.00001525878906,"y":1043.9999389648438,"wires":[]},{"id":"20a26fcd.f2d89","type":"trigger","z":"6524ce52.cafd2","name":"","op1":"","op2":"","op1type":"pay","op2type":"payl","duration":"180","extend":false,"units":"min","reset":"","bytopic":"all","topic":"topic","outputs":2,"x":410,"y":1280,"wires":[["1b645571.e1b01b","ddcb339c.d115b"],["ddcb339c.d115b"]]},{"id":"ddcb339c.d115b","type":"change","z":"6524ce52.cafd2","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":700,"y":1140,"wires":[[]]},{"id":"da171be6.24f9b","type":"inject","z":"6524ce52.cafd2","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":160,"y":1120,"wires":[["7e9720ad.01208","ce38cc84.62ab","20a26fcd.f2d89"]]},{"id":"1b645571.e1b01b","type":"debug","z":"6524ce52.cafd2","name":"","active":false,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","statusVal":"$moment().add(180, 'minutes').format(\"ddd HH:mm:ss\")\t","statusType":"jsonata","x":430,"y":1320,"wires":[]},{"id":"ce38cc84.62ab","type":"debug","z":"6524ce52.cafd2","name":"","active":false,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","statusVal":"$moment().add(180, 'minutes').format(\"ddd HH:mm:ss\")\t","statusType":"jsonata","x":430,"y":1160,"wires":[]}]
Two examples one for a resetting trigger when another message is received and one for when that option is not set.