thanks to EE, I googled "execute sql task datetime parameter" to find out how to configure the Execute SQL Task to apply the result of the query to the variable, so I could pass it as a parameter downstream.

Used this url

https://www.simple-talk.com/sql/ssis/ssis-basics-using-the-execute-sql-task-to-generate-result-sets/.

General

ResultSet Single row

Connection Type: OLE DB

Connection: (my named oledb conection)

SQLSourceType: Direct Input

SQL statement : SQL Query

Parameter Mapping

variablename: user:: DateStamp

Direction: Input

data Type: VARCHAR

Parameter name : 0

Parameter size : -1

Result Set

Result Name SQLDateTime

VariableName User::DateStamp

Expressions

N/A