Add different time periods in R (Create new total age column) - r

Question

I have time periods as specified below. I have the age in terms of different units of time (Year, Month, Weeks, Days) but would like to add the different time units to give me one total age. My issue is that the functions I am finding in R when trying to convert the time units take the year as a specific year and the month as a specific month rather than a number of years or a number of months.
Could you show me how to add say, 68 years to 5 months to 3 days and 2 hours and so on. In other words to create a column with the total age in years which I can then easily convert to the total age in months and so on?
> head(KimAge)
# A tibble: 6 x 7
ID Years Months Weeks Days Hours
<dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 1 68 5 NA NA NA
2 2 70 2 NA NA NA
3 3 NA NA NA NA NA
4 4 23 NA NA NA NA
5 5 NA NA NA 3 NA
6 6 NA NA NA NA NA
In some pseudo-code, I am trying to write something like the pseudo-code below
KimAge$TotalAge = as.Year(Years) + as.month(Months) + as.week(Weeks) + as.days(Days) + as.hour(Hours)

Answer 1

To create the total age column you can use the lubridate library:
library(dplyr)
library(lubridate)
KimAge <- tibble(years = c(68, 70, NA, 23, NA, NA),
months = c(5, 2, NA, NA, NA, NA),
weeks = c(NA, NA, NA, NA, NA, NA),
days = c(NA, NA, NA, NA, 3, NA),
hours = c(NA, NA, NA, NA, NA, NA))
# convert NA to zero
KimAge[is.na(KimAge)] <- 0
# time to duration
KimAge$TotalAge <- duration(year = KimAge$years,
month = KimAge$months,
week = KimAge$weeks,
day = KimAge$days,
hour = KimAge$hours)
If you know the birthdate and death date:
KimAge <- tibble(birth = c("1974/03/21 12:40",
"2004/9/2 00:10",
"2014/12/12 00:00",
"2012/2/1 0:0"),
death = c("2020/03/11 16:40",
"2020/7/2 14:00",
"2021/1/4 23:01",
"2012/3/2 0:0"))
KimAge$birth <- parse_date_time(KimAge$birth, "ymd H:M")
KimAge$death <- parse_date_time(KimAge$death, "ymd H:M")
KimAge$TotalAge_d <- as.duration(KimAge$death - KimAge$birth)
KimAge$TotalAge_i <- as.interval(KimAge$birth , KimAge$death)
# interval version
KimAge$years = KimAge$TotalAge_i %/% years(1)
KimAge$months = KimAge$TotalAge_i %% years(1) %/%months(1)
KimAge$days = KimAge$TotalAge_i %% years(1) %% months(1) %/% days(1)
For more information on lubridate https://lubridate.tidyverse.org/. Read the differences between lubridate::period() and lubridate::interval().