# clocktime

Time-of-day and ISO 8601 duration types for APIs, GraphQL, and SQL.

## Install

```bash
go get gitea.auvem.com/go-toolkit/clocktime
```

## ClockTime

```go
ct, err := clocktime.ParseClockTime("09:30:00")
t := ct.Time() // 1970-01-01 UTC anchor
```

- Strict `HH:MM:SS` parsing via [ParseClockTime]
- SQL `TIME` columns: stored as `[]byte` / string; scanned from `time.Time`, `[]byte`, or `string`
- Optional fields: use `*ClockTime`; `IsZero()` is true only for nil pointers
- Midnight `00:00:00` is valid; use `IsMidnight()` to detect it

## ISODuration

```go
d, err := clocktime.ParseISODuration("PT1H30M")
ns := d.Duration()
```

- JSON/GQL: ISO 8601 strings
- SQL: `int64` nanoseconds (strings accepted on scan)
- Calendar durations (`P1M`, `P1Y`) convert to approximate nanoseconds and may not round-trip

## gqlgen

Both types implement `MarshalGQL` / `UnmarshalGQL`.