Add Unix Timestamp and Javascript Timestamp converstions to the date/time app

Use set node to modify time in the value field

check my mini help to find modification to your needs
if $json.body.listingDateTimeOnZillow is unix miliseconds
{{DateTime.fromSeconds($json.body.listingDateTimeOnZillow/1000).toFormat(‘yyyy-MM-dd HH:mm:ss’)}}
// Output: 2023-10-13 17:23:58

{{DateTime.fromSeconds(new Date().getTime()/1000).toFormat(‘yyyy-MM-dd HH:mm:ss’)}}
// Output: 2023-10-13 17:23:58

{{Math.floor(new Date().getTime() / 1000)}}
// Output: 1573041058

{{new Date().getTime()}}
// Output: 1573041058024

{{new Date().toISOString()}}
// Output: 2019-11-06T11:50:58.025Z

{{new Date().toString()}}
// Output: Wed Nov 06 2019 12:50:58 GMT+0100 (Central European Standard Time)

{{new Date().toLocaleDateString()}}
// Output: 11/6/2019

{{ new Date().toISOString(“en-GB”, {timeZone: "Europe/Moscow"}).replace(‘T’, ’ ').slice(0, -5) }}
// Output ISO: 2022-12-04 21:26:27

2023-02-21T22:43:59+03:00 to unix - {{Date.parse( $json.body.date) / 1000}}
if 2023-04-03T08:20:33Z - {{ DateTime.fromISO($json.create_time).toFormat(‘yyyy-MM-dd HH.mm’) }}

plusmonths:
{{DateTime.fromISO($json[“body”][“date”]).plus({ months: $json[“months”] }).toUnixInteger()}}

{{Math.floor(new Date().getTime() / 1000)+30}} - unix+30 secomds

another example - Google Calendar How do I set up a notification in advance? - #3 by nle