Convert a time that may be inconsistently or inconveniently formatted from Microsoft Excel to a numeric number of seconds between 0 and 86400.

Usage

excel_time_to_numeric(time_value, round_seconds = TRUE)

time_value: A vector of values to convert (see Details)
round_seconds: Should the output number of seconds be rounded to an integer?

A vector of numbers >= 0 and <86400

time_value may be one of the following formats:

numericThe input must be a value from 0 to 1 (exclusive of 1); this value is returned as-is.
POSIXlt or POSIXctThe input must be on the day 1899-12-31 (any other day will cause an error). The time of day is extracted and converted to a fraction of a day.
characterAny of the following (or a mixture of the choices):
- A character string that is a number between 0 and 1 (exclusive of 1). This value will be converted like a numeric value.
- A character string that looks like a date on 1899-12-31 (specifically, it must start with "1899-12-31 "), converted like a POSIXct object as described above.
- A character string that looks like a time. Choices are 12-hour time as hour, minute, and optionally second followed by "am" or "pm" (case insensitive) or 24-hour time when hour, minute, optionally second, and no "am" or "pm" is included.