Сергей Лялин

function dataURLtoFile(dataurl, filename) {
      let arr = dataurl.split(','),
        mime = arr[0].match(/:(.*?);/)[1],
        bstr = atob(arr[1]),
        n = bstr.length,
        u8arr = new Uint8Array(n);
      while (n--) {
        u8arr[n] = bstr.charCodeAt(n);
      }
      return new File([u8arr], filename, { type: mime });
    }

saveScanStat.onclick = () => {
                let now = new Date()
                let dataForLS = {}
                dataForLS = JSON.parse(localStorage.getItem(`sostav${sostav}`))
                if (dataForLS == null) {
                    dataForLS = {}
                }
                dataForLS[docId] = {
                    day: `${now.getDate()}`,
                    month: `${1 + now.getMonth()}`,
                    a40: `${a40}`
                }

                localStorage.setItem(`sostav${sostav}`, JSON.stringify(dataForLS))
            }

let dataForLS = {}
                let sostavNumber = document.querySelector("#b-footer > div > div:nth-child(2) > input:nth-child(2)").value
                dataForLS = JSON.parse(localStorage.getItem(`sostav${sostavNumber}`))
                let counter = {}
                let needMonth = Number(document.querySelector("#month").value.substr(5, 7))
                for (let key in dataForLS) {

                    if (dataForLS[key].month == needMonth) {
                        if (counter[dataForLS[key].day] == null) {
                            counter[dataForLS[key].day] = 0
                        }
                        counter[dataForLS[key].day]++
                    }

                }
                console.log(counter);
            }