Timestamps

Fields named CreatedAt and UpdatedAt are kept up to date for you, whether they come from ant.Basetype Base struct{ … }Base is an optional embeddable model base. or not. You never have to set them.

What moves them

type Note struct {
	ID        int64
	CreatedAt time.Time
	UpdatedAt time.Time
	Text      string
}

Action	CreatedAt	UpdatedAt
Insertfunc (t *Table[T]) Insert(ctx context.Context, entities ...*T) errorInsert writes entities and the new entities related to them, parents first, in one transaction, so either all are saved or none are., InsertManyfunc (t *Table[T]) InsertMany( ctx context.Context, entities []*T, options ...InsertOption, ) (int64, error)InsertMany writes many rows quickly, in multi-row statements inside one transaction, and returns how many were inserted., Upsertfunc (t *Table[T]) Upsert(ctx context.Context, e *T, conflict *Conflict) (bool, error)Upsert inserts e, or follows conflict if a unique constraint already holds the row.	Set	Set
SaveChangesfunc (c *Context) SaveChanges(ctx context.Context) errorSaveChanges writes every change to tracked entities in one transaction: inserts and updates with parents first, then deletes with children first. with a change		Moved
SaveChanges with no change		Left alone
Bulk Updatefunc (q *Query[T]) Update(ctx context.Context, a ...Assignment) (int64, error)Update applies assignments to every matching row and returns the number of rows changed.		Moved

Times are stored at the database's precision, so the value on your struct matches what's in the table. If you set a time yourself, it's kept on insert, and ant.Set(&U.UpdatedAt, t)func Set[V any](field *V, v V) AssignmentSet assigns v to field. wins on update.

A clock for tests

ant.WithNowfunc WithNow(now func() time.Time) OptionWithNow sets the clock for automatic timestamps, which suits tests. lets you set the clock, which keeps tests predictable.

now := time.Date(2026, 1, 1, 12, 0, 0, 0, time.UTC)

clock := ant.WithNow(func() time.Time { return now })

db, err := ant.Open[AppDB](ctx, postgres.Dialect, dsn, clock)

Unix seconds

ant.UnixTimetype UnixTime = meta.UnixTimeUnixTime is a time stored as whole seconds since 1970. stores a time as an integer, and it's kept up to date all the same.

type Stamped struct {
	ID        int64
	CreatedAt ant.UnixTime
	UpdatedAt ant.UnixTime
}

Opting out

b.NoTimestampsfunc (b *ModelBuilder[E]) NoTimestamps()NoTimestamps stops CreatedAt and UpdatedAt being maintained. turns all of this off for one model, and leaves the fields as you set them.

func (Note) Configure(b *ant.ModelBuilder[Note]) {
	b.NoTimestamps()
}

To move a parent's UpdatedAt when a child is written, see Touch.

See it tested: tests/features/lifecycle/timestamps_test.go