Convert timestamp to UTC from AST or DST

Convert timestamp to UTC from AST or DST

Usage

adcp_correct_timestamp(dat, rm = TRUE)

Arguments

dat

Data frame with at least one column timestamp_ns (long or wide format).

rm

Logical argument. If TRUE the original timestamp_ns column will be removed.

Value

Returns dat with timestamp_utc in true UTC.

Details

For the raw ADCP data, the timestamp column is in the timezone of the deployment date (e.g., "AST" if deployed in November to March and "DST" if deployed in March to November). The timestamp does NOT account for changes in daylight savings time.

adcp_read_text() assigns the timestamp a timezone of "UTC" to avoid NA values during the beginning of daylight savings time (e.g., 2019-03-10 02:30:00 is NOT a valid time for the "America/Halifax" timezone).

adcp_correct_timestamp() converts each timestamp to true UTC by adding 3 hours if the deployment date was during daylight savings, or 4 hours if the deployment date was during Atlantic Standard Time.

The earliest timestamp is used to define the original timezone (AST/DST).