# ABP Framework v4.x to v5.0 Migration Guide

## MongoDB

ABP Framework will serialize the datetime based on [AbpClockOptions](https://docs.abp.io/en/abp/latest/Timing#clock-options) start from 5.0, before `DateTime` values in MongoDB are [always saved as UTC](https://mongodb.github.io/mongo-csharp-driver/2.13/reference/bson/mapping/#datetime-serialization-options).

You can disable this behavior by configure `AbpMongoDbOptions`.
```cs
services.Configure<AbpMongoDbOptions>(x => x.UseAbpClockHandleDateTime = false);
```

## Angular UI

See the [Angular UI Migration Guide](Abp-5_0-Angular.md).