Expression function request: an extra mode to ConvertDate() that takes a knows date format, independent from the user's system format.
ConvertDate(datetime_string, mode=0) - current behaviour, default mode 0
ConvertDate(ISO8601_date, mode=1) - new mode, string as known date format with optional time:
YYYY-MM-dd
YYYY-MM-dd HH:mm
YYYY-MM-dd HH:mm:ss
(4 digits for year, 1 or 2 digits for others, 24h clock)
Not exactly ISO8601, but easy. This allows writing code what works regardless of the user's location.
Alternatively: ConvertDate(year, month, day, hour, min, sec)