Start the Timer on specific date/ time & customizing the duration with formula

[PurpleDeveloper]

Hi Everyone,

I am having hard time with timer control in power apps. I need to start the timer on specific date/ time which is the created on date of the post.

I did with the option of selecting the button On Select property as below,

OnSelect = UpdateContext({TimerGo: true})

and setting the Start of timer as Timer Go.

Start = TimerGo

However, still the timer starts here on function of button but looking to run on specific date/ time whether it's with Button property or timer's start property.

Also, looking for setting up the duration of 10 hours from created on date/time as customized duration with below formula,

DateDiff((DateAdd(ThisItem.defaultdate,10,Hours)),ThisItem.defaultdate,Milliseconds)

where default date is same as created on but the customized column for editing later as per user's requirement. However, this formula doesn't work.

Is there any way to make the Timer Start on specific date/ time and calculating duration with customized formula?

Any help is really appreciated!

Thank you!

[RusselThomas]

Hi @PurpleDeveloper ,

If I understand this correctly, then I think your timer needs a timer 😊

Essentially, you can set up a global timer for your app that keeps track of real time.  You can do this by adding a timer and setting its Duration to 1000 and OnTimerEnd: property to something like this;

Set(gvarGlobalTime, Now())

Then you can use the OnTimerStart or OnTimerEnd properties to check a datetime value against the gvarGlobalTime and perform actions based on whether the time matches - or you might have sub-timers that do this and they might trigger other sub-timers who might even trigger more sub-timers. 

Be aware though that each running timer in your app takes up CPU cycles as each timer runs in millisecond increments, regardless of their duration, so too many concurrently running timers may significantly slow your app down.  Their actions on each cycle also contribute to runtime performance.  1 has little to no impact - 20 running at the same time might start causing visible performance issues. 

Also be aware that some people have reported their app max session time is usually around 24-hours, whereupon the user might need to re-authenticate, so if you're running something in unattended 'kiosk' mode for long durations, this might have an impact.

Lastly - if I'm understanding your duration formula intent - it looks like you just want the timers to run for 10 hours from when they start - so wouldn't your duration just be 10 hours in milliseconds, (36000000), with the timer set to not repeat?

Kind regards,

RT

[PurpleDeveloper]

Hi Russel, 

Thanks for your response.

Regarding the duration formula, yes I need 10 hours and set the duration as 36000000 milliseconds. However, I am looking for a custom formula with respect to date column from table. The reason for doing so, if in case user need that to be changed for particular post we should be able to do from dataverse end instead of changing the duration in app itself for every form.

For example, we have a date/ time column "defaultdate" and it has value "Mar 04, 2021 10:50:00" and I was putting the below formula for calculating 10 hours of duration,

DateDiff((DateAdd(ThisItem.defaultdate,10,Hours)),ThisItem.defaultdate,Milliseconds)

However, it's not working out.

On the part of global timer, can you help me with steps instructions to follow for start and end properties. As here I am trying to start the timer on the date picked up from "defaultdate" column.

Really appreciate your help on this!

Thank you!

[RusselThomas]

Hi @PurpleDeveloper ,

I'm not sure I understand the full implications of your scenario, so I'll try answer as best I can and please forgive me if I miss what you're trying to say.

Duration:

Looking at your formula - if you're putting this on the Duration: property of the timer, you're essentially just specifying a set (fixed) duration for the timer to run - which if I understood correctly, will be 10 hours from the default time.  

You formula is saying;

"Subtract thisdate from (thisdate + 10hrs) = 10hrs, represented in milliseconds = 36000000".

The answer to this formula will always be 10hrs, no matter what your date value is - so changing the date will not change your duration. 

It's the same as saying "x + 5 - x = 5 " - regardless of what "x" is, your answer will always be 5.

So if you're wanting to somehow change duration, then duration needs to come from somewhere you can change the "5" value - not the "x" value.  

Global Timer:

Think of your global timer as a clock - that's its primary function.

The issue with using Now() as a time reference in PowerApps, is that Now() only refreshes when you calculate it.  So if you set a var "varTime" to Now() it will be the time at the point you set it. 

If you check "varTime" ten minutes later, it will still be the time from when it was set ten minutes ago - you need to reset "varTime" to Now() again to get the current time.

Hence, the timer, which we can use to set Now() every second, and this keeps track of "current Time".

Once you've got a current Time reference, you can then start doing calcs on datetime values to determine how far from current Time they are.  To be honest, I'm not sure you need a "clock" timer, as I think I may have misunderstood your original post, but this is the principle.

So the only thing you need on your global timer is the following, either OnTimerStart:, or OnTimerEnd: - just not both as it's a waste of processing;

Set(gvarCurrentTime, Now())

Also make sure to pop it on your home page and set Auto Pause: to false.

Now, whenever you use gvarCurrentTime in your expressions, it will be the current time, which means you can see how far a certain datetime value is from right now (either in the past or in the future) using DateDiff().

This can allow you to set 'alarms' for certain times, or trigger things when they are a certain distance from timestamps you specify.  

I'm not sure if this is helping you - perhaps you can explain a little more about your scenario and we can work out the best way to achieve what you want?

Kind regards,

RT

[PurpleDeveloper]

Hi Russel,

Thank you so much for your reply. It make sense. Much appreciate your time and help with this problem.

However, I got it solved by applying below formula in "Duration" of timer.

DateDiff(Now(),(DateAdd(ThisItem.defauldate,10,Hours)),Milliseconds)

And in Text :

Text(Time(0,0,(Timer1.Duration-Timer1.Value)/1000),"hh:mm:ss")

Now, the timer for each post starts automatically (AutoStart = 'True') & counts from 10 hours until 0. Even, if user exits the app and launch it again, it resumes and keeps the countdown running for remaining time.

There is one weird thing happening, when we click the timer, it stops which we need to get rid off. We do not want user to stop the timer.

All properties (OnSelect, OnTimerEnd, OnTimerStart, AutoPause, Repeat, Reset) are set to FALSE though.

Any idea what could be the cause behind it?

Thank you!

[RusselThomas · Accepted solution]

Hi @PurpleDeveloper ,

That's great!  The difference between Now(), when the screen loads the first time for each app session, and a time 10 hours from the item date - "Now" I get it 🙂

You can either set the DisplayMode: of the timer to DisplayMode.View, or you can hide the timer altogether by setting it's Visible: property to false and just put a text label representing the timer using the exact same text formula you have above.  Both will achieve the same thing.

Hope this helps,

RT

[PurpleDeveloper]

Hi Russel,

Thanks you for your response. It really helps.

Appreciate all your support and help in this! 🙂

[IanMawdsley]

Hi, I have a similar need, tried the code above but got errors, ThisItem not found, can you help please.

Thanks in advance

Ian Mawdsley