calendar_widen() widens x to the specified precision. It does so
by setting new components to their smallest value.
Each calendar has its own help page describing the precisions that you can widen to:
Details
A subsecond precision x cannot be widened. You cannot widen from, say,
"millisecond" to "nanosecond" precision. clock operates under the
philosophy that once you have set the subsecond precision of a calendar,
it is "locked in" at that precision. If you expected this to multiply
the milliseconds by 1e6 to get to nanosecond precision, you probably
want to convert to a time point first, and use time_point_cast().
Generally, clock treats calendars at a specific precision as a range of
values. For example, a month precision year-month-day is treated as a range
over [yyyy-mm-01, yyyy-mm-last], with no assumption about the day of the
month. However, occasionally it is useful to quickly widen a calendar,
assuming that you want the beginning of this range to be used for each
component. This is where calendar_widen() can come in handy.
Examples
# Month precision
x <- year_month_day(2019, 1)
x
#> <year_month_day<month>[1]>
#> [1] "2019-01"
# Widen to day precision
calendar_widen(x, "day")
#> <year_month_day<day>[1]>
#> [1] "2019-01-01"
# Or second precision
calendar_widen(x, "second")
#> <year_month_day<second>[1]>
#> [1] "2019-01-01T00:00:00"