The times are right, the confusion is the "GMT+/-" bits are misleading.
Central Daylight Time is noted there as GMT-5, which is sort-of-true only if you put Daylight Savings in. Ignoring DST, Central is GMT-6. Central is 6 time zones away, but the
effect is 5 while the USA does daylight-savings time.
Similarly, the UK is operating on "British Summer Time" (BST) which is GMT+1, even though Greenwich is
inside the UK.
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All you need to know is that
during the summer everything written will tell you the right times, but may stop making sense later