ScriptRunner Scripted Field Not Available for JQL Search

[Shawna Morris]

I've added two ScriptRunner Scripted Fields to my Jira instance... 

1. Sprint Start Date
2. Sprint End Date

These fields will look at the defined start/end dates for the Sprint and stuff those into the two custom fields appropriately. Everything works fine... I can pull these fields into columns on the "Search for issues" however when I try and use these two new fields as part of a JQL Search, they're not available.

This is just one of my Scripts to return the Sprint Start Date... 

// Required Imports
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.Issue
import java.text.SimpleDateFormat;
import java.util.Date.*;
import com.atlassian.jira.issue.customfields.searchers.TextSearcher

// Get the current issue key
Issue issue = issue

// Get a pointer to the CustomFieldManager
def customFieldManager = ComponentAccessor.getCustomFieldManager()

// Get a pointer to the sprint CF
def sprintCf = customFieldManager.getCustomFieldObjectByName("Sprint")

// Stop the values on screen showing old cached values
enableCache = {-> false}

// Define a new Java Simple Date Format
SimpleDateFormat sdfDate = new SimpleDateFormat("dd/MMM/YYYY");

// Get the Start Date for the Sprint
Date sprintStartDate = issue.getCustomFieldValue(sprintCf)?.startDate?.first()?.toDate()

// Return the output Date
return sprintStartDate

I re-indexed Jira after the field was implemented. 

What am I doing wrong? Why can't I use JQL to Search on these fields? 

Thanks in advance!