invalid time_start format (use ISO 8601, e.g. 2026-01-02T15:

Error message

invalid time_start format (use ISO 8601, e.g. 2026-01-02T15:04:05Z): %w

What it means

The time_start parameter of a temporal_window search could not be parsed as a valid ISO 8601 timestamp by parseGraphitiTime. The wrapped error (%w) carries the underlying parse failure. This is an argument-format validation error raised before any network call.

Source

Thrown at backend/pkg/tools/graphiti_search.go:348

	}
	return input
}

// handleTemporalWindowSearch performs time-bounded search
func (t *graphitiSearchTool) handleTemporalWindowSearch(
	ctx context.Context,
	groupID string,
	args GraphitiSearchAction,
	observationObject *graphiti.Observation,
) (string, error) {
	// Validate temporal parameters
	if args.TimeStart == "" || args.TimeEnd == "" {
		return "", fmt.Errorf("time_start and time_end are required for temporal_window search")
	}

	timeStart, err := parseGraphitiTime(args.TimeStart)
	if err != nil {
		return "", fmt.Errorf("invalid time_start format (use ISO 8601, e.g. 2026-01-02T15:04:05Z): %w", err)
	}

	timeEnd, err := parseGraphitiTime(args.TimeEnd)
	if err != nil {
		return "", fmt.Errorf("invalid time_end format (use ISO 8601, e.g. 2026-01-02T15:04:05Z): %w", err)
	}

	if timeEnd.Before(timeStart) {
		return "", fmt.Errorf("time_end must be after time_start")
	}

	maxResults := args.MaxResults.Int()
	if maxResults <= 0 {
		maxResults = DefaultTemporalMaxResults
	}

	req := graphiti.TemporalSearchRequest{
		Query:       args.Query,

View on GitHub (pinned to ea665308ba)

Solutions

Format time_start as ISO 8601, e.g. 2026-01-02T15:04:05Z
Use an explicit UTC 'Z' offset to avoid timezone parsing issues
Check the wrapped %w cause in the error for the exact parse failure

Example fix

// before
{"time_start": "August 1st 2026"}
// after
{"time_start": "2026-08-01T00:00:00Z"}

Defensive patterns

Strategy: validation

Validate before calling

ts, err := time.Parse(time.RFC3339, args.TimeStart)
if err != nil {
    return fmt.Errorf("time_start must be ISO 8601 (RFC3339), e.g. 2026-01-02T15:04:05Z: %w", err)
}

Type guard

func validISO8601(s string) bool {
    _, err := time.Parse(time.RFC3339, s)
    return err == nil
}

Prevention

Format all timestamps with time.Format(time.RFC3339) at the source
Use explicit UTC 'Z' offsets
Reject human-readable date strings before invoking the tool

When it happens

Trigger: Passing time_start in a non-ISO-8601 format such as "01/02/2026", "yesterday", "2026-08-01 10:00" (space instead of T may fail depending on the parser), or a value with an invalid timezone.

Common situations: LLM agents emitting human-readable dates; locale-formatted timestamps; milliseconds vs seconds confusion; missing timezone designator.

Related errors

AI-assisted analysis of vxcontrol/pentagi@ea665308ba (2026-09-01). Data as JSON: /api/errors/ff213126d6474391. Report an issue: GitHub.