Run the following query to get a list of the subscribers of every Calendar in your Confluence site: 

SELECT tc."NAME" AS "Calendar Name", um."username" AS "Subscriber" 
FROM "AO_950DC3_TC_SUBCALS" tc
LEFT JOIN "user_mapping" um ON um."user_key" = tc."CREATOR"
WHERE "PARENT_ID" IS NULL AND "SUBSCRIPTION_ID" IS NOT NULL
ORDER BY 1,2

1. Replace the <calendar_name> with the name of the calendar that you wish to find its creator.

   select BANDANACONTEXT from  BANDANA where BANDANAVALUE like '%X-WR-CALNAME:<calendar_name>%';

2. Now Run the next query. Replace the <BANDANACONTEXT> with the previous query result

   select BANDANAVALUE from  BANDANA where BANDANACONTEXT = '<BANDANACONTEXT>';

3. The output of this query should be similar to the one below: 
   
   

   |
       <string>{"id":"1c0ecd7a-0cf8-4db2-a3ec-11706f28ddfe","color":"subcalendar-turquoise","description":"ert","name":"trte","spaceKey":"","creator":"admin","timeZoneId":"Asia/Calcutta"}</string>
        |
       |
       <string>{"id":"6dc2caf6-5261-4de2-a3e7-eff19ffbebba","color":"subcalendar-blue2","description":"sdfsd","name":"dfsg","spaceKey":"","creator":"admin","timeZoneId":"Asia/Calcutta"}</string> 
        |

   
   From the result, you can see the creator name, in this case it is 'admin'

Run the following query to get the users who created every Calendar in your Confluence site:

SELECT tc."NAME" AS "Calendar Name", um."username" AS "Creator", to_timestamp(CAST(tc."CREATED" AS bigint) / 1000) AS "Creation Date"
FROM "AO_950DC3_TC_SUBCALS" tc
LEFT JOIN "user_mapping" um ON um."user_key" = tc."CREATOR"
WHERE "PARENT_ID" IS NULL AND "SUBSCRIPTION_ID" IS NULL
ORDER BY 1,2

SELECT um.lower_username as creator, tc.NAME as calendar_name, tc."SPACE_KEY" as Space, from_unixtime(round(tc.created/1000)) as creation_date
FROM AO_950DC3_TC_SUBCALS tc
JOIN user_mapping um ON um.user_key = tc.CREATOR
WHERE tc.PARENT_ID IS NULL
ORDER BY creator;

SELECT um.lower_username as creator, tc.NAME as calendar_name, tc."SPACE_KEY" as Space, dateadd(second,cast(cast(tc.CREATED AS nvarchar(255)) AS bigint)/1000,'19700101 00:00:00:000') as creation_date
FROM AO_950DC3_TC_SUBCALS tc
JOIN user_mapping um ON um.user_key = tc.CREATOR
WHERE tc.PARENT_ID IS NULL
ORDER BY creator;

SELECT um.lower_username as creator, tc.NAME as calendar_name, tc."SPACE_KEY" as Space, to_date('01.01.1970','dd.mm.yyyy') + to_number(tc.created)/1000/60/60/24 AS creation_date
FROM AO_950DC3_TC_SUBCALS tc
JOIN user_mapping um ON um.user_key = tc.CREATOR
WHERE tc.PARENT_ID IS NULL
ORDER BY creator; 

If you need to filter by Calendar name, just add a WHERE clause based on tc."NAME" column.