theRefdate - Simple and Fast Date Manipulation on Character Strings

Provides simple and fast date manipulation functions operating on character strings in one of three formats: 'DD.MM.YYYY' (default), 'YYYY-MM-DD' or 'YYYYMMDD'. The format is chosen once per R session. Functions include extraction of day, month, and year components, computation of differences between two dates, and addition or subtraction of months. "DD" is ignored in the calculations, therefore a date like 31.02.2026 is a valid in- or output. That's why it is so fast.