2018-04←  2018-05 looping  →2018-06

20180501_0000 UTC	20180502_0000 UTC	20180503_0000 UTC	20180504_0000 UTC
20180505_0000 UTC	20180506_0000 UTC	20180507_0000 UTC	20180508_0000 UTC
20180509_0000 UTC	20180510_0000 UTC	20180511_0000 UTC	20180512_0000 UTC
20180513_0000 UTC	20180514_0000 UTC	20180515_0000 UTC	20180516_0000 UTC
20180517_0000 UTC	20180518_0000 UTC	20180519_0000 UTC	20180520_0000 UTC
20180521_0000 UTC	20180522_0000 UTC	20180523_0000 UTC	20180524_0000 UTC
20180525_0000 UTC	20180526_0000 UTC	20180527_0000 UTC	20180528_0000 UTC
20180529_0000 UTC	20180530_0000 UTC	20180531_0000 UTC

2018-04←  2018-05 looping  →2018-06