Bash script to post recurrent time entries on Toogl (e.g.: dailies)

post_toggl_time_entries.sh

#!/usr/bin/env bash

declare -r  MONTH="${1:-"$(date +'%m')"}"
declare -r  MY_TOGGL_TOKEN="${MY_TOGGL_TOKEN?"Variable MY_TOGGL_TOKEN not declared"}"
declare -r  UTC_NEW="$(TZ=UTC date +'%I')"
declare -ri MY_TIME=$(date +'%H')
declare -ri TZ_DIFF="$(( ${MY_TIME/0} - ${UTC_NEW/0} ))"

## How-to get the Project ID (wid): https://github.com/toggl/toggl_api_docs/blob/master/chapters/projects.md
declare -r PROJECT_ID="${PROJECT_ID?"Variable PROJECT_ID not declared"}"
## How-to get the Workspace ID (wid): https://github.com/toggl/toggl_api_docs/blob/master/chapters/workspaces.md
declare -r WORKSPACE_ID="${WORKSPACE_ID?"Variable WORKSPACE_ID not declared"}"
## Must to be in seconds
declare -r ENTRY_DURATION="${ENTRY_DURATION?"Variable ENTRY_DURATION not declared"}"

## Diff between user timezone and UTC
[[ "${TZ_DIFF}" == \-* ]] && declare -r TOGGLE_TZ="-0${TZ_DIFF//-/}" || declare -r TOGGLE_TZ="+0${TZ_DIFF}"

## It will POST the entries with days between 9 and 13, 16 and 20
## 
for i in {9..13} {16..20} ; do
  [[ "${#i}" -eq 1 ]] && declare DAY="0${i}" || declare DAY="${i}"
  curl -su "${MY_TOGGL_TOKEN}:api_token" \
    -H "Content-Type: application/json" \
    -d "{
        \"time_entry\": {
          \"description\": \"Daily Team X\",
          \"billable\": false,
          \"duration\": ${ENTRY_DURATION},
          \"start\": \"2019-${MONTH}-${DAY}T10:00:00${TOGGLE_TZ}:00\",
          \"pid\": ${PROJECT_ID},
          \"wid\": ${ENTRY_DURATION},
          \"created_with\": \"curl\"
        }
      }" -X POST https://www.toggl.com/api/v8/time_entries | jq
  sleep 1s
  curl -su "${MY_TOGGL_TOKEN}:api_token" \
    -H "Content-Type: application/json" \
    -d "{
      \"time_entry\": {
        \"description\": \"Daily Team Y\",
        \"billable\": false,
        \"duration\": ${ENTRY_DURATION},
        \"start\": \"2019-${MONTH}-${DAY}T09:30:00${TOGGLE_TZ}:00\",
        \"pid\": ${PROJECT_ID},
        \"wid\": ${ENTRY_DURATION},
        \"created_with\": \"curl\"
      }
    }" -X POST https://www.toggl.com/api/v8/time_entries | jq
  sleep 1s
done