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Null Start Date on Planner Task

I'm trying to pass a null value for the start date on 'Create a task'. The start date is listed in the step (and documentation) as an optional field, yet it won't run the flow without it. This is the failure feedback that I'm receiving:


The request is invalid: Cannot convert the literal '' to the expected type 'Edm.DateTimeOffset'. 


  "error": {
    "message""The request is invalid:\r\nCannot convert the literal '' to the expected type 'Edm.DateTimeOffset'.",
    "innerError": {


My intent is to allow the task to be created with or without a start date, then updated through a separate flow if a start date is assigned or modified later. This is the expression that I'm using on the create flow 'Start Date Time' step: 


if(empty(triggerBody()?['Assigned_x0020_Start_x0020_Date']), null, triggerBody()?['Assigned_x0020_Start_x0020_Date'])


Any thoughts for getting the step to accept a task with no start date?

Community Support Team
Community Support Team

Re: Null Start Date on Planner Task

Hi @ nhalvorson,


Where is the task’s start date saved in?

Could you please share a screenshot of your flow's configuation?


I have made a test on my side, you couldn’t insert the null value in the “Start Date Time” field of the “Create a task” action of Planner connector.


For you situation, you could add a Condition to check if the “start date” is null,the expression in the Condition as below:


if the “start date” is null, then the flow wouldn’t insert the “start date” in the “Start Date Time” field of the “Create a task” action, if the “start date” isn’t null, then the flow would insert the “start date” in the “Start Date Time” field of the “Create a task” action.


Alice Zhang

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