Checks twitter accounts daylight savings movements.

DSTcheck.R

# modify this line
questionable_screennames <- c("put","screennames","here")
###

library(rtweet)
library(dplyr)
library(lubridate)
library(ggplot2)
library(scales)
library(ggthemes)

## gather tweets- this number of tweets per account 
## if everyone has tweeted 3000+ times this is going to be 
## 15 mins * number of acocunts checked

testacs <- get_timelines(questionable_screennames, n=3000)

nzdst <- ISOdatetime(2020,9,27,1,59,59,tz = "Pacific/Auckland")
audst <- ISOdatetime(2020,10,4,1,59,59,tz = "Australia/Sydney")

prenz7am <- with_tz(ISOdatetime(2020,9,20,7,0,0,tz = "Pacific/Auckland"), "UTC")
nzdst7am <- with_tz(ISOdatetime(2020,10,27,7,0,0,tz = "Pacific/Auckland"), "UTC")
annotatepre7 <- ISOdatetime(2018,7,1,hour(prenz7am), minute(prenz7am), 
                            second(prenz7am), tz="UTC")
annotatedst7 <- ISOdatetime(2018,7,1,hour(nzdst7am), minute(nzdst7am), 
                            second(nzdst7am), tz="UTC")

graphlimits = c(ISOdatetime(2018,7,1,0,0,0,tz = "UTC"), 
  ISOdatetime(2018,7,2,0,0,0,tz = "UTC"))

testacs %>% 
  filter(created_at > (nzdst - days(14))) %>%
  mutate(inday = ISOdatetime(2018,7,1,hour(created_at), minute(created_at), 
                             second(created_at), tz="UTC"),
   byday = floor_date(created_at, unit="day"),
   when = case_when(created_at < nzdst ~ "Pre NZ DST",
                    created_at > audst ~ "AU DST",
                    TRUE ~ "NZ DST"),
   cloaked_screen_name = as.numeric(factor(screen_name))) %>%
  ggplot(aes(x=byday, y=inday, colour=when)) + geom_point(size=0.2) +
  scale_y_datetime(date_breaks = "6 hours",
    labels = date_format("%H:%M",tz = "UTC"),
    limits = graphlimits) + theme_tufte() +
  xlab("Day (in UTC time)") + ylab("Hour of Day (UTC)") + 
  scale_colour_colorblind() + 
  facet_wrap(~ cloaked_screen_name, ncol=6) +
  annotate("line", x=c(nzdst - days(15), nzdst-days(1)), y=annotatepre7, linetype="dashed") +
  annotate("line", x=c(nzdst, nzdst+days(12)), y=annotatedst7, linetype="dashed") +
  annotate("line", x=c(nzdst - days(15), nzdst-days(1)), y=annotatepre7 - hours(7)) +
  annotate("line", x=c(nzdst, nzdst+days(12)), y=annotatedst7 - hours(7)) +
  ggtitle("Tweet times (UTC) of 'fringe' accounts saying they were New Zealanders.
          Solid line: midnight in NZ, Dashed line: 7am in NZ") + 
  theme(strip.background = element_rect(fill= "#FFFFFF", colour="#EFEFEF"),
        strip.placement = "inside",
        panel.background = element_rect(fill = "#FFFFFF", colour = "#FFFFFF"),
        panel.spacing = unit(1.5, "lines"), 
        plot.background = element_rect(fill = "#FAFAFA", colour = NA),
        axis.text.x = element_text(angle = 90))

Example output