Database

[{_id:"d751b295-6597-4a0b-bd64-89b0fbaac812",yada:{type:"yada",id:"nkfsh000136"},audit:{created_at:"2022-10-03T09:09:22.672144670Z"},type:"yada",payload:{encounter:{provider:{first_name:"yada",last_name:"Doublecheck",npi:"1366553539"},appointment:{scheduled:"2022-10-03T09:04:10.588Z",start:"2022-09-19T15:04:05Z",end:"2022-09-19T15:14:03Z",duration:"955"},codes:{icd10:["R21"]},pharmacy:"HEB Pharmacy yada #77 (001)"}},vendor:"yada"}]

Query

db.collection.update({},[{$set:{"audit.created_at":{"$dateAdd":{"startDate":{$toDate:"$audit.created_at"},"unit":"millisecond","amount":1}}}}])

Result