Elasticsearch date range query on date field with added buffer days - date

Question

I have to get records (training) wherein I have a start_date, and I have to get all records that have not yet ended. So I don't have an end_date field, but just the start date, so end_date is start_date + 60 days.
So what I need comprises all results that have "start_date" less than equal to "now" and "start_date + 60 days" greater than equal to "now" i.e. "now" is between start_date and "start_date + 60 days".
So here's what I am trying. But I know "on_demand_start_date+60d" is incorrect. Can anyone help, how can this be done?
"must": [
{
"range": {
"on_demand_start_date+60d": {
"gte": "now"
}
}
},
{
"range": {
"on_demand_start_date": {
"lte": "now"
}
}
}
]
Below is a sample document:
{
"_index": "cdc_sse_content",
"_type": "doc",
"_id": "cdc_sse_publish_1140",
"_score": null,
"_source": {
"country": "us",
"event_source_time_zone": "",
"source": "CVENT",
"iSAPIRecord": true,
"index_type": "content",
"content_title": "***Test - API March 04 - 1",
"event_technology": [
"Cloud & Computing",
"Collaboration",
"Services (CX)"
],
"language_code": "en",
"application_name": "event-selector",
"event_type": "Hybrid event",
"event_region": [
"North America"
],
"event_time_zone": "UTC",
"cdc_page_url": "https://www.google.com?EID=<95929>",
"event_end_date": "2022-02-05T01:00",
"event_filters": "",
"created_by": "shaiwsha",
"live_stream_end_date": null,
"marketing_owner": "tparida",
"event_on-demand_details": "",
"search_filter_lables": [
"On-demand"
],
"kafka": {
"consumer_group": "sseadmin",
"partition": 0,
"offset": 181002,
"topic": "SSEAdminContentPublished",
"key": null
},
"updated_by": "shaiwsha",
"publish_date": "2022-02-15",
"event_start_date": "2022-02-04T17:00",
"status": "active",
"eid": "95929",
"es_index_fail": false,
"cdc_id": "event-selector_1140",
"event_image_url": "https://www.cisco.com/c/dam/assets/events/i/event-selector/2021/rsa_global_events_page_br_dark_600x400.png",
"description": "Test 1 - This is a sample Hybrid event, that should the event type,Hybrid with City and country displayed. This is a sample In-Person that should disp",
"selector_id": "cdc_event-selector_publish_1140",
"event_livestream_url": "",
"locale": "en_us",
"event_registration_url": "https://sandbox-www.cvent.com/d/p7qgmk/4W?&EID=95929",
"event_live_stream_details": "",
"event_city": "Santa Clara",
"event_registration_and_location_details": "",
"#version": "1",
"event_details": "",
"start_date": "2022-02-07T19:37",
"registration_start_date": "2022-02-18T09:00",
"event_industry": [
"Manufacturing"
],
"event_language": [
"Cantonese",
"Dutch",
"English"
],
"event_state": "California",
"live_stream_start_date": null,
"on_demand_url": "https://www.google.com",
"on_demand": [
"On-demand"
],
"#timestamp": "2022-03-15T07:28:08.821Z",
"registration_end_date": "2022-02-20T09:00",
"recent_search_published_date": "2022-03-10T14:17:30.320Z",
"event_country": "USA",
"featured_event": [
"Featured event"
],
"created_date": "2022-03-10T10:08:05.801Z",
"last_update_ts": "2022/3/10 14:19:5",
"updated_date": "2022-03-10T14:19:05.693Z"
},
"sort": [
1643994000000
]
}