omissis/go-jsonschema

package types

import (
    "errors"
    "fmt"
    "strings"
    "time"
)

var ErrTimeNotJSONString = errors.New("cannot parse non-string value as a time")

type SerializableTime struct {
    time.Time
}

func (t SerializableTime) MarshalJSON() ([]byte, error) {
    return []byte("\"" + t.Format(time.TimeOnly) + "\""), nil
}

func (t *SerializableTime) UnmarshalJSON(data []byte) error {
    stringifiedData := string(data)
    if stringifiedData == "null" {
        return nil
    }

    if !strings.HasPrefix(stringifiedData, "\"") || !strings.HasSuffix(stringifiedData, "\"") {
        return ErrTimeNotJSONString
    }

    timeWithoutQuotes := stringifiedData[1 : len(stringifiedData)-1]

    parsedTime, err := time.Parse(time.TimeOnly, timeWithoutQuotes)
    if err != nil {
        return fmt.Errorf("unable to parse time from JSON: %w", err)
    }

    t.Time = parsedTime

    return nil
}