I’m trying to adjust the UTC time into EET time in a gantt type of chart, where I want to plot some Cron schedulings which are in the UTC time. UTC to EET conversion does not seem to take into account the DST, e.g. for AA it should be +03:00 hours, not +02:00 hours. Here is the code. How can I adjust the time conversion and Y-axis in the plot?

library(jsonlite)
library(dplyr)
library(ggplot2)
library(scales)
library(lubridate)

# JSON data
json_data <- '[
{"SchedulingName": "AA", "cronExpr": "0 3 * * *"},
{"SchedulingName": "AB", "cronExpr": "30 2 * * *"},
{"SchedulingName": "AC", "cronExpr": "30 2 * * *"},
{"SchedulingName": "AD", "cronExpr": "0 6 * * *"},
{"SchedulingName": "ADD", "cronExpr": "30 2 * * *"},
{"SchedulingName": "ADER", "cronExpr": "55 1,7 * * *"},
{"SchedulingName": "ADF", "cronExpr": "9 9 * * *"},
{"SchedulingName": "ERE", "cronExpr": "0 0 * * 0"},
{"SchedulingName": "DFA", "cronExpr": "0 5 * * *"},
{"SchedulingName": "DFD", "cronExpr": "45 6 * * *"},
{"SchedulingName": "GREW", "cronExpr": "30 2 * * *"},
{"SchedulingName": "ASDFA", "cronExpr": "9 9 * * *"},
{"SchedulingName": "AFERE", "cronExpr": "30 4 * * *"},
{"SchedulingName": "DFAARE", "cronExpr": "30 2 * * *"},
{"SchedulingName": "DFARE", "cronExpr": "9 9 * * *"},
{"SchedulingName": "DAFAD", "cronExpr": "30 2 * * *"},
{"SchedulingName": "ADWER", "cronExpr": "0 5 * * *"},
{"SchedulingName": "OASDFAS", "cronExpr": "0 3 * * *"},
{"SchedulingName": "ASDPFAS", "cronExpr": "50 2 * * *"},
{"SchedulingName": "ASDFASDF", "cronExpr": "45 3 * * *"},
{"SchedulingName": "AERED", "cronExpr": "0 22 * * *"},
{"SchedulingName": "ASDFAER", "cronExpr": "30 5,12 * * *"},
{"SchedulingName": "AREWVSD", "cronExpr": "9 9 * * *"},
{"SchedulingName": "SARAER", "cronExpr": "30 2 * * *"},
{"SchedulingName": "QEFHF", "cronExpr": "0 3 * * *"},
{"SchedulingName": "AFEREADF", "cronExpr": "30 3 * * *"},
{"SchedulingName": "UTKY", "cronExpr": "30 6 * * *"},
{"SchedulingName": "IUOU", "cronExpr": "0 5 * * *"},
{"SchedulingName": "KYDF", "cronExpr": "0 7 * * *"},
{"SchedulingName": "DSARAE", "cronExpr": "0 0 * * *"},
{"SchedulingName": "KYRT", "cronExpr": "9 9 * * *"},
{"SchedulingName": "WERRYHN", "cronExpr": "0 1 * * *"},
{"SchedulingName": "FHSUR", "cronExpr": "30 12 * * *"},
{"SchedulingName": "PIU", "cronExpr": "30 23 * * *"},
{"SchedulingName": "ASDGYHBDV", "cronExpr": "0 3 * * *"},
{"SchedulingName": "KYIUY", "cronExpr": "0 19 * * *"},
{"SchedulingName": "IRETH", "cronExpr": "9 9 * * *"},
{"SchedulingName": "JTUT", "cronExpr": "31 23 * * *"},
{"SchedulingName": "HRURJU", "cronExpr": "0 20 * * *"}
]'

# Convert JSON to DataFrame
cron_jobs <- fromJSON(json_data)
head(cron_jobs)

# Process data to extract times and create POSIXct timestamps
cron_jobs <- cron_jobs %>%
  mutate(
    Minute = as.numeric(sub("^(\d+)\s.*", "\1", cronExpr)),
    Hour = as.numeric(sub("^\d+\s(\d+).*", "\1", cronExpr)),
    StartTime = as.POSIXct(paste("2024-01-01", Hour, Minute), format = "%Y-%m-%d %H %M", tz = "UTC"),
    EndTime = StartTime + 720,  # Add 12 minutes for task duration
    StartTime = as_datetime(StartTime, tz = 'Europe/Helsinki'),
    EndTime = as_datetime(EndTime, tz = "Europe/Helsinki")
  )
head(cron_jobs)

# Sort the factor levels for better visualization
cron_jobs <- cron_jobs %>%
  arrange(SchedulingName) %>%
  mutate(SchedulingName = factor(SchedulingName, levels = rev(unique(SchedulingName))))

# Date range for the Gantt chart
full_day_start <- force_tz(as.POSIXct("2024-01-01 00:00", format = "%Y-%m-%d %H:%M", tz = "UTC"), tzone = "Europe/Helsinki")
full_day_end <- force_tz(as.POSIXct("2024-01-02 00:00", format = "%Y-%m-%d %H:%M", tz = "UTC"), tzone = "Europe/Helsinki")

# Create Gantt chart
ggplot(cron_jobs, aes(x = SchedulingName, y = StartTime, xend = SchedulingName, yend = EndTime)) +
  geom_segment(size = 3, color = "red") +
  coord_flip() +
  scale_y_datetime(
    breaks = seq(full_day_start, full_day_end, by = "1 hour"),
    labels = date_format("%H:%M"),
    limits = c(full_day_start, full_day_end)
  ) +
  labs(title = "Cron Schedule Gantt Chart (EET)", x = "Task", y = "Time") +
  theme_minimal() +
  theme(
    axis.text.x = element_text(angle = 90, hjust = 1)
  )