如何在Rmarkdown中使用数据表（DT包）打印非UTC时间戳？

Question

I have some timestamps stored in different time-zones that I would like to include in a datatable using DT package within a rmarkdown document.

I would like to display the timestamp in the stored time-zone but for some reason datatable converts it to UTC. The behaviour when I use print is what I want but the format is not nice.

How can I achieve the same behaviour with datatable and print ?

Here a minimal working example of the rmarkdown file:

---
title: "MinorQ"
output: html_document
---

```{r setup}
library(DT)
df=data.frame(timestamp=as.POSIXct("2017-01-01 12:34:56",tz="CET"))
df$tzone=attr(df$timestamp,"tzone")
datatable(df)
print(df)
```

Answer 1

As mentioned in my comment you could just convert your POSIXct elements to character:

input <- format(as.POSIXct("2017-01-01 12:34:56", tz = "CET"), format = '%F %T %Z')
str(input)

# chr "2017-01-01 12:34:56 CET"

This does not mean that you cannot use different timezones. When reading from the table you could use gsub to get your dates with the correct timezone:

# First gsub: remove all capital letters (so only date and time remain)
# Sec.  gsub: remove all characters exept capital letters (so only CET, UTC, etc. remain).

out <- as.POSIXct(gsub(input, pattern = "[A-Z]", replacement = ""), 
                  format = '%F %T', 
                  tz     = gsub(input, pattern = "[^A-Z]", replacement = ""))

str(out)
# POSIXct[1:1], format: "2017-01-01 12:34:56"

lubridate::tz(out)
# [1] "CET"