Criticize the bash script?

Question

linux

I am very far from scripts and development. It took some time to make a simple script. Check, pliz, who does not complicate. The script works. Threw it into fcron for execution once a minute. But sometimes messages in telegrams fall with a delay of 3 to 20 minutes.

#!/bin/bash
KEY="xxxxxxx:yyyyyyyyyyy" #ключ телегграм-бота
TARGET="-4343905834509345098345" #id группы телеграм
URL1="https://api.telegram.org/bot$KEY/sendMessage"
output=$(curl -s 'https://экзампл.ком/api/posts/json')
OLD_TIME=$(echo $(cat /root/telegram/previous_post_time.json)) #время создания предыдущего поста, записанного в epoch-time.
GET_TIME=$(echo $output | jq .posts[0].created) #вытаскиваем из запроса время создания последнего поста
if (( $GET_TIME > $OLD_TIME )); then
    TIME=$(echo $GET_TIME>/root/telegram/previous_post_time.json) #записываем новое значение времени создания поста.
    GET_URL=$(echo $output | jq -r .posts[0]._links[1].href)                               
    GET_USER=$(echo $output | jq -r .posts[0].user.login)   
    URL=$(echo $GET_URL>/root/telegram/url.json)                                                        
    TEXT="$GET_USER $GET_URL"
    PAYLOAD="chat_id=$TARGET&text=$TEXT&parse_mode=Markdown"
    curl -s --max-time 10 --retry 5 --retry-delay 2 --retry-max-time 10 -d "$PAYLOAD" $URL1 > /dev/null 2>&1 &
else
    exit 0
fi
exit 0

Answer 1

if (( $GET_TIME > $OLD_TIME )); then

Here is an arithmetic comparison.
Most likely, the block is executed with an error all the time, because it is not clear what is in $GET_TIME, and there is hardly a recognizable command. Unless something intelligible accidentally hits. If you give examples of what gets into these variables, it will be clearer.
You need to compare not dates, but timestamps