Q:

How to convert string "2019-10-09T06:07:05.888Z" as calendar date and time

Please help me to find a solution for converting "2019-10-09T06:07:05.888Z" as a calendar time stamp. I tried the following methods,
> format(as.POSIXlt("2019-10-09T06:07:05.888Z"), "%Y-%m-%d %H:%M:%OS3")
[1] "2019-10-09 00:00:00.000"

> as.POSIXct("2019-10-09T06:07:05.888Z", format="%Y-%m-%d %H:%M:%OS")
[1] NA

A:

With as.POSIXct, we can first convert the data into POSIXct class and then use format to display the output in the format we want.
temp <- as.POSIXct("2019-10-09T06:07:05.888Z",format = "%Y-%m-%dT%H:%M:%OS", tz = "UTC")
format(temp, "%Y-%m-%d %H:%M:%OS3")
#[1] "2019-10-09 06:07:05.888"

Or with lubridate
format(lubridate::ymd_hms("2019-10-09T06:07:05.888Z"), "%Y-%m-%d %H:%M:%OS3")

