#!/bin/sh

gawk '
BEGIN {
    ONE_DAY = 60*60*24

    start_time = mktime("2019 08 07 00 00 00")

    ct = start_time
    while (1) {
        ct += ONE_DAY
        print strftime("%Y-%m-%d", ct)
    }
}' |
gawk '
BEGIN {
    FS = "-"
}

function array_length(a, e,c) {
    for (e in a) { c++ }
    return c
}

function same_elements_q(a,  i,j,l,c) {
    l = array_length(a)
    for (i=1; i<=l; i++) {
        c = 0
        for (j=1; j<=l; j++) {
            if ("" a[i] == "" a[j]) {
                c++
            }
        }
        if (c >= 2) {
            return 1
        }
    }

    return 0;
}

{
    y = $1
    m = $2
    d = $3
    sub(/^0/, "", m)
    sub(/^0/, "", d)
    split(y m d, a, "")
    if (!same_elements_q(a)) {
        print $0
    }
}' |
head -n 1