Mongoose date field - Set default to date.now + N days
You can add 7 days converted to milliseconds to current date like this
default: new Date(+new Date() + 7*24*60*60*1000)
or even like this
default: +new Date() + 7*24*60*60*1000
UPDATE
Please check the @laggingreflex comment below. You need to set function as default value:
default: () => new Date(+new Date() + 7*24*60*60*1000)
default: () => Date.now() + 7*24*60*60*1000
This will be enough