Is there a way to capture week number of the current year using Nintex workflow? I know how to capture that using SharePoint calculated value but need to get it in my workflow.
If all is well you should be able to convert the calculated formula into a Nintex formula using inline functions. If however, these functions prove insufficient, you could consider using a helper list where you have your calculated column for the weekno and a date. In the workflow you create a new item in that list with your date, store its ID, Pause for 1 minute (to allow the item to be created), query list/list lookup the calculated column value with the weekno and finally delete the item.