R Markdown

library(leaflet)
library(htmltools)
library(lubridate)
## 
## Attaching package: 'lubridate'
## The following objects are masked from 'package:base':
## 
##     date, intersect, setdiff, union
location <- data.frame(
  lat = 41.0082,
  lng = 28.9784,
  popup_text = "Hagia Sophia, Istanbul"
)

passed_time <- format(Sys.Date() %m-% years(1), "%d. %B %Y")

show_time <- tags$div(
  style = "background: rgba(255, 255, 255, 0.8); padding: 10px; border-radius: 5px; font-weight: bold; color: black;",
  paste("Datenstand:", passed_time)
)

map_obj <- leaflet(data = location) %>%
  addTiles() %>%
  addMarkers(popup = ~popup_text) %>%
  addControl(
    html = as.character(show_time),
    position = "topleft"
  )
## Assuming "lng" and "lat" are longitude and latitude, respectively
map_obj