How do i make a Date type constraint in KoBoToolbox

[wroos]

Hello,
add constraint to ${A5} >= ${A3} and a good constraint_message.
See also recent post:

Using preceding DATE-TIME question's response to constraint a question

I would like to use response to a given question as a constraint value with comparison operators for restricting the response to subsequent question. eg Q1: start_time Q2: end_time what should be the constraint syntax to ensure that the end time entered is not less than the Start time?

You should use two date type questions here with appearance (XLS column) = year…

Side-note: Also, you may need also to take care in your questionnaire flow that both variables might be empty (for reality). Maybe you will need to add to the constraint … or ${A5} = ‘’ (for empty string)