# Chronometer in perspective **URL:** \ **Category:** Ignition\ **Tags:** ignition81, perspective\ **Created:** [September 25, 2023, 7:38pm UTC](https://forum.inductiveautomation.com/t/chronometer-in-perspective/79604 "2023-09-25T19:38:07Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![ryan.white](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/ryan.white/32/73193_2.png) [@ryan.white](https://forum.inductiveautomation.com/u/ryan.white)\ **Post date:** [September 25, 2023, 7:48pm UTC](https://forum.inductiveautomation.com/t/chronometer-in-perspective/79604/2 "2023-09-25T19:48:29Z")
I would have a global memory tag that is the timestamp of when the door opened. You can have another tag with an expression along the lines of `max(0, dateDiff({[default]PathToDoorOpenTimestamp}, now(), 'second'))`. From there you can then use the value of that expression tag to do additional formatting to get your time elapsed as HH:mm or mm or ss. For your timer display, you can set an expression on the display property that is `{[Path]ToTimeElapsedTag}>300`, and then have that label display the formatted time elapsed value. > [@Expression binding timer that counts up](https://forum.inductiveautomation.com/t/expression-binding-timer-that-counts-up/77381): > > Hi, I want a timer that counts upwards in the format minutes:seconds where seconds counts to 60 then resets to 00, 01, 02 and so on and minutes counts on indefinitely. I use two params, a startTime and currentTime. Right now, the below works-ish, but I'd like to know if there is a way to format the numbers with a zero in front until 10 seconds as right now they simply go 1, 2, 3. concat(tostr(toint(floor(dateDiff({view.custom.start},{view.custom.now},"minute")))),":", tostr(toint(floor(dateDiff… should help some with figuring out how to get the seconds elapsed value into the format that you want --- _[View the full topic](https://forum.inductiveautomation.com/t/chronometer-in-perspective/79604)._