tzconvert

func ConvertRangeLocalToUTC ¶

func ConvertRangeLocalToUTC(startLocal, endLocal float64, utcOffset int) (utcStart, utcEnd float64)

ConvertRangeLocalToUTC converts a time range from local to UTC time. Handles ranges that may cross midnight.

Parameters:

• startLocal, endLocal: Start and end hours in local time
• utcOffset: The timezone offset from UTC

Returns: Start and end hours in UTC.

func ConvertRangeUTCToLocal ¶

func ConvertRangeUTCToLocal(startUTC, endUTC float64, utcOffset int) (localStart, localEnd float64)

ConvertRangeUTCToLocal converts a time range from UTC to local time. Handles ranges that may cross midnight.

Parameters:

• startUTC, endUTC: Start and end hours in UTC
• utcOffset: The timezone offset from UTC

Returns: Start and end hours in local time.

func LocalToUTC ¶

func LocalToUTC(localHour float64, utcOffset int) float64

LocalToUTC converts a local hour to UTC given a UTC offset. Example: LocalToUTC(11.5, -4) converts 11:30 EDT to 15:30 UTC Example: LocalToUTC(10.0, 8) converts 10:00 CST to 02:00 UTC

Parameters:

• localHour: Hour in local time (0-24, can include fractional hours)
• utcOffset: The timezone offset from UTC (negative for west, positive for east)

Returns: UTC hour (0-24), properly wrapped for day boundaries.

func ParseTimezoneOffset ¶

func ParseTimezoneOffset(timezone string) int

ParseTimezoneOffset extracts the numeric offset from a timezone string. For IANA timezones, it uses Go's time package to get the current offset. Examples:

• "UTC-4" returns -4
• "UTC+8" returns 8
• "UTC" returns 0
• "America/New_York" returns -4 or -5 depending on DST
• "Pacific/Auckland" returns 12 or 13 depending on DST
• Invalid input returns 0

func UTCToLocal ¶

func UTCToLocal(utcHour float64, utcOffset int) float64

UTCToLocal converts a UTC hour to local hour given a UTC offset. Example: UTCToLocal(15.5, -4) converts 15:30 UTC to 11:30 EDT (UTC-4) Example: UTCToLocal(2.0, 8) converts 02:00 UTC to 10:00 CST (UTC+8)

Parameters:

• utcHour: Hour in UTC (0-24, can include fractional hours like 15.5 for 15:30)
• utcOffset: The timezone offset from UTC (negative for west, positive for east) Examples: -4 for EDT, -7 for PDT, 0 for GMT, 8 for CST (China)

Returns: Local hour (0-24), properly wrapped for day boundaries.