2017-12←  2018-01 looping  →2018-02

20180101_0000 UTC	20180102_0000 UTC	20180103_0000 UTC	20180104_0000 UTC
20180105_0000 UTC	20180106_0000 UTC	20180107_0000 UTC	20180108_0000 UTC
20180109_0000 UTC	20180110_0000 UTC	20180111_0000 UTC	20180112_0000 UTC
20180113_0000 UTC	20180114_0000 UTC	20180115_0000 UTC	20180116_0000 UTC
20180117_0000 UTC	20180118_0000 UTC	20180119_0000 UTC	20180120_0000 UTC
20180121_0000 UTC	20180122_0000 UTC	20180123_0000 UTC	20180124_0000 UTC
20180125_0000 UTC	20180126_0000 UTC	20180127_0000 UTC	20180128_0000 UTC
20180129_0000 UTC	20180130_0000 UTC	20180131_0000 UTC

2017-12←  2018-01 looping  →2018-02