I've found a way to save Instant by converting it into OffsetDateTime and use bindObject.

I still think, that if we have bindTimestamp we should be able to put Calendar in it.

I am also confused, that every bind method except date/time binding methods increased index by one, so I've added it to my last commit (let me know if it wasn't a bug and I'll revert it).

You would also need to update the sqldelight jdbc driver api spec this is checked during the gradle build for breaking changes to the public api

The java.time.Instance type is currently not supported in Postgres JDBC https://jdbc.postgresql.org/documentation/query/#table51-supportedjava-8-date-and-time-classes

As a Java Instant has to be stored as a timezone type - You must ensure that the storage column type is TIMESTAMPTZ

Rather than resorting to legacy types, a SqlDelight Adapter could be used to convert between Instant and OffsetDateTime as you may prefer Instant in your data class model rather than OffsetDateTime e.g

import java.time.Instant;

CREATE TABLE Requests (
   ping TIMESTAMPTZ AS Instant,
   ipaddress TEXT
);

val pingAdapter = object : ColumnAdapter<Instant, OffsetDateTime> {
    override fun decode(databaseValue: OffsetDateTime): Instant = databaseValue.toInstant()
    override fun encode(value: Instant): OffsetDateTime = value.atOffset(ZoneOffset.UTC)
}

I am also confused, that every bind method except date/time binding methods increased index by one, so I've added it to my last commit (let me know if it wasn't a bug and I'll revert it).

Yes - JDBC is position based (1..n) so that would be correct to update it

You would also need to update the sqldelight jdbc driver api spec

I really don't know neither the syntax of the spec nor what it is based on. Isn't it somehow generated?

You would also need to update the sqldelight jdbc driver api spec

I really don't know neither the syntax of the spec nor what it is based on. Isn't it somehow generated?

You can use the tasks ./gradlew :drivers:jdbc-driver:apiCheck to validate and ./gradlew :drivers:jdbc-driver:apiDump to update the spec