Try duration.inSeconds and mintues component.
MATCH (x:Test)
RETURN duration.inSeconds(x.datetime1,x.datetime2).minutes
Here are the Component groups
| Component Group | Component |
|---|---|
| inMonths | years, quarters, months |
| inDays | weeks, days |
| inSeconds | hours, minutes, seconds, milliseconds, microseconds, nanoseconds |
For more reference check
https://neo4j.com/docs/cypher-manual/current/values-and-types/temporal/#cypher-temporal-accessing-components-durations