I'd use a second, hidden timer counting DOWN from 45:00 to 00:00, with an "OnCountdownEnd" trigger setup to start the other clock and bring it on screen.

Your Companion shortcut then starts both 45min timers together.

Maybe here?
https://www.kaylarecord.net

As far as I know you can't have a timer start in negative. Triggers can carry out multiple actions - I'd probably for safety do

1) Reset count up to zero
2) Start count up
3) display count up

Exactly "on overlayIn" trigger to main 45:00 vmix input title timer and then to this vmix input the "oncountdown completed" for the 2nd additional timer

Thanks for all your suggestions guys - i now have it working.

Will def have a look at vmix_soccer_clock, but for the time being I do have a working 'fully vmix' solution.

I need to refine it, so I only have 3 inputs (scoreboard, clock normal time, clock additional time), with basic scripting in place and the use of triggers.

Once I have it sorted (still work in progress, but does work in tests) - I will put in here my final solution, so anyone searching in the future of something similar can see the solution I used, and have that as a starting point

Never dealt with Pages before - but I think that is a great idea..... Need to work on that. Thanks for the suggestion (and another learning opportunity)

So I have it all working - thanks to everyone who helped.

Page 1.png (19kb) downloaded 2 time(s). Page 2.png (24kb) downloaded 0 time(s). Page 3.png (29kb) downloaded 3 time(s). Page Field Names.png (25kb) downloaded 0 time(s).

GTDesigner - see above for screenshots
Transition in – everything hidden
Page 1 – ScoreBoard Only
Page 2 – ScoreBoard plus Normal Timer
Page 3 – ScoreBoard plus Additional Time Timer


5 Shortcuts (streamdeck)
1 – Scoreboard Only ScriptStart ScoreBoardVisible
2 – 1st Half ScriptStart ScoreBoard1stHalf
3 – 2nd Half ScriptStart ScoreBoard2ndHalf
4 – 1st Half Extra Time ScriptStart ScoreBoard1stExtra
5 – 2nd Half Extra Time ScriptStart ScoreBoard2ndExtra

Scripts:
ScoreBoardVisable
Function=OverlayInput1IN&Input=ScoreBoard
Function=SelectIndex&Value=1&input=ScoreBoard

ScoreBoard1stHalf
Function=ChangeCountdown&Input=ScoreBoard&SelectedName=Clock.Text&Value=00%3A00%3A00 (this sets the start of the timer, so 00:00 for 1st Half, 45:00 for 2nd half etc)
Function=SetCountdown&Input=ScoreBoard&SelectedName=Clock.Text&Value=00%3A45%3A00 (this sets the end of the timer, so 45:00 for 1st Half, 90:00 for 2nd half etc)
Function=ChangeCountdown&Input=ScoreBoard&SelectedName=Additional.Text&Value=00%3A00%3A00 (this sets the additional timer start back to 0)
Function=SetCountdown&Input=ScoreBoard&SelectedName=Additional.Text&Value=00%3A55%3A00 (this sets the additional timer end back to 55 - just so it does not set off oncompletion)
Function=SetText&Input=ScoreBoard&SelectedName=Half.Text&Value=45:00+ (this just sets the additional time visible (left side))
Function=StartCountdown&Input=ScoreBoard&SelectedName=Clock.Text (this starts the timer)
Function=OverlayInput1IN&Input=ScoreBoard (this sets the scoreboard input to overlay 1)
Function=SelectIndex&Value=2&input=ScoreBoard (this sets the scoreboard to Page 2 - which is the normal match clock)

Repeated for other halves, with adjustment to time in 1st 2 rows (starting time, ending time eg 45:00 to 90:00
NB 90 mins needs to be 1 hour 30 mins

Scoreboard – Triggers
OnCountdownCompleted selectindex scoreboard value = 3
OnCountdownCompleted ChangeCountdown scoreboard value = 00:00:00 (for additional text)
OnCountdownCompleted StartCountdown scoreboard value = 1 (for additional text)

This selects Page 3 (Additional Time), then sets Additional Timer to 00:00, and then starts that timer

This may not be the most elaborate way of doing this (but significantly better than other options i had originally) - and most 'competent' coders will probably be pulling their hair out! But it works for me, and can give someone looking for something similar ideas of how i done it.