I would like to submit a proposal to convert Neo4 Date and Time object into ISO strings when returning these values from the driver.

The driver returns properties and values, which are defined in Neo4j as DateTime, Date or Time, in their native Java format. That means, the ISO string 1970年01月01日T00:00:00.000Z

return datetime('1970-01-01T00:00:00.000Z') as datetime

will be returned as Neo4j DateTime object and serialised into JSON as

{
 "datetime": {
 "year": 1970,
 "month": 1,
 "day": 1,
 "hour": 0,
 "minute": 0,
 "second": 0,
 "nanosecond": 0,
 "timeZoneOffsetSeconds": 0
 }
}

However, this format is not very useful when working with JavaScript. I know there are methods like DateTime.toStandardDate() to get a plain JS Date, but there are still some drawbacks:

1. the Neo4j database connection is usually abstracted or hidden by a backend layer, that means downstream services receive the serialised JSON format instead of the Neo4j DateTime object that provide the conversion functions toStandardDate().

2. other services that receive the data as JSON have to install the neo4j driver package to create a Neo4j DateTime object via its constructor and then convert it to a JS Date. Or they have to implement their own function to create a JS Date from this format.

3. the conversion from Neo4j DateTime to JS Date looses timezone information, because JS Date is not timezone aware and always converts dates into local time. The conversion of 1970年01月01日T00:00:00.000Z from Neo4j DateTime to JS Date and back to Neo4j DateTime alters the original ISO string and adds a timezone offset of 3600 seconds. Of course, it is still the original date and time, but the timezone information was changed. That is the reason we usually avoid working with the native JS Date and instead use libraries like Luxon, Moment, or Day.js that retain the original timezone.

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These drawbacks could be solved if the driver would be able to convert the DateTime, Date and Time objects as ISO strings instead of the corresponding objects. For example, as an option disableTemporalTypes like the conversion of Neo4j Integers to native JS numbers:

var driver = neo4j.driver(
 'neo4j://localhost',
 neo4j.auth.basic('neo4j', 'password'),
 { 
 disableLosslessIntegers: true, 
 disableTemporalTypes: true // => convert datetime to ISO
 }
)

Or it could be implemented as mappedResultTransformer for the new Driver.executeQuery() with a conversion function for each native Java type:

const result = await driver.executeQuery("query", params, {
 resultTransformer: neo4j.resultTransformer.mappedResultTransformer({
 map: (record) => record.toObject({ 
 converter: {
 dateTime: (value: DateTime) => value.toString() // convert datetime to ISO
 }),
 collect: records => records
 })
})

Conversion of DateTime, Date and Time to ISO strings would also help, because JavaScript Date doesn't support date-only 1970年01月01日 and time-only 00:00:00.000Z. In this cases, the conversion to JS Date potentially alters real information.