The code defines a series of functions related to time. The constant
conversionFns, converts days, hours, minutes, and seconds into seconds. The function,
toSeconds, converts a given amount of time in a given unit into seconds. The second function,
unixTimeInSeconds, returns the current time in Unix time (i.e. the number of seconds since January 1, 1970). The third function,
calcExpiry, calculates when a given duration will expire. The final function,
formatPeriods, formats a given duration into a more human-readable form.