How to define string-based date identifier in TX Enhanced Connector

Hi,
In one of my CData connections i have a RSD file for an endpoint with the follwing code for startPeriod and endPeriod
 

<api:set attr="out.TodayDate" 					value="[dummy | CURRENT_DATE()]"/>
<api:set attr="out.StartPeriodYear" 				value="[out.TodayDate | year()]"/><api:set attr="out.StartPeriod" 					value="[out.StartPeriodYear | insert(4,01)]"/>
<api:set attr="out.EndPeriod" 					value="[out.StartPeriodYear | insert(4,12)]"/> 

This i refer to in POST statement in 

{
        "fromValue": "{startPeriod}",
        "restrictionType": ">=",
        "columnName": "period",
        "relDateCrit": ""
    },
    {
        "fromValue": "{endPeriod}",
        "restrictionType": "<=",
        "columnName": "period",
        "relDateCrit": ""
    }

Is this the correct way - instead of hard coding? 

And then, in the window above:

{
        "fromValue": "{startPeriod}",
        "restrictionType": ">=",
        "columnName": "period",
        "relDateCrit": ""
    },
    {
        "fromValue": "{endPeriod}",
        "restrictionType": "<=",
        "columnName": "period",
        "relDateCrit": ""
    }