Search notes:

R function: strftime

strftime converts a date-time object into a character vector. strptime does the opposite. 
y2000 <- as.Date("2000-01-01")

class(y2000)
# [1] "Date"

y2000_100days <- y2000 + 100

txt <- strftime(y2000_100days, '%F') # ISO 8601

class(txt)
# [1] "character"

txt
# 2000-04-10
Github repository about-r, path: /functions/strftime.R

See also

strftime
Index to (some) R functions

Index

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:78 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(78): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/developm...', 1788383113, '216.73.217.21', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/development/languages/R/functions/strftime(57): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78