Function adjust_timestamp 

pub fn adjust_timestamp(
    datetime: &str,
    adjustment: &str,
    timezone: &str,
) -> Result<AdjustedTimestamp, TruthError>

Adjust a timestamp by adding or subtracting a duration.

Arguments

• datetime — An RFC 3339 datetime string
• adjustment — A duration string (e.g., "+2h", "-30m", "+1d2h30m", "+1w")
• timezone — An IANA timezone name for interpreting day-level adjustments

Duration Format

Must start with + or -, followed by one or more components:

• Nw — weeks
• Nd — days (timezone-aware: same wall-clock time, not +24h across DST)
• Nh — hours
• Nm — minutes
• Ns — seconds

Components can be combined: +1d2h30m, -2w3d.

Errors

Returns TruthError::InvalidDatetime if the datetime cannot be parsed, TruthError::InvalidTimezone if the timezone is invalid, or TruthError::InvalidDuration if the adjustment string cannot be parsed.