I am also having this issue. I'm trying to put a scope variable into the countdown attribute and it fails with this error:

Error: [$parse:syntax] Syntax Error: Token 'selectedNotification.countdown' is unexpected, expecting [:] at column 3 of the expression [{{selectedNotification.countdown}}] starting at [selectedNotification.countdown}}].

However the fix doesn't appear to be working for me.

The fix works without the {{ }}
Ex:
countdown="timeLimit"

Same issue, same fix. The fix works without the {{ }}.
Why don't you ask for a pull?

Ask for pull, please.

$scope.$broadcast 'timer-set-countdown', secs

This works.

Adding an ng-if worked for me, ensuring the variable was ready to go before the directive was rendered.

So from:

<timer end-time="myVariable">{{minutes}} minute{{minutesS}}</timer>

To:

<timer ng-if="myVariable" end-time="myVariable">{{minutes}} minute{{minutesS}}</timer>

My example hasn't been tested for countdown, but I'm pretty sure it will translate.

I don't think that adding countdown: '=' would be a good way to do things, as this is already set up with countdownattr: '=countdown', and it is countdownattr that does all the magic.

You just need to delay rendering the directive until the point in the $digest cycle when your variable has been evaluated with an ng-if.

Hope this helps.

EDIT:
More info on Angular's rendering cycle here: [ http://stackoverflow.com/questions/24615103/angular-directives-when-and-how-to-use-compile-controller-pre-link-and-post?rq=1 ]

Yes this was the reason. The variable was not set yet. I fixed it using a django template variable instead of a angular variable which was not always set.
Your method with ng-if sounds good too.

@FelixFortis I tried that before, but the problem with that is first off end-time doesn't work at all, second, the moment it is assigned it will start with whatever time that was last rendered, then takes about a sec to update to the current value, meaning you will get a 1 or 2 sec flash. So this is not optimal in my opinion.

+1 for ng-if solution....

works fine:
<timer ng-if="vm.countdown" countdown="vm.countdown"

NaN:
<timer countdown="vm.countdown"

+1 for ng-if solution

+1 for ng-if solution ..i tried many ways except ng-if...Wowww its worked perfectly

👍 for @wtczk it work for me thanks you :)