CLDR doesn't formally have offsets. What it has is data like:
<metazone type="America_Eastern">
<long>
<generic>Eastern Time</generic>
<standard>Eastern Standard Time</standard>
<daylight>Eastern Daylight Time</daylight>
</long>
<short>
<generic>ET</generic>
<standard>EST</standard>
<daylight>EDT</daylight>
</short>
</metazone>
de.xml
<metazone type="America_Eastern">
<long>
<generic>Nordamerikanische Ostküstenzeit</generic>
<standard>Nordamerikanische Ostküsten-Normalzeit</standard>
<daylight>Nordamerikanische Ostküsten-Sommerzeit</daylight>
</long>
</metazone>
(Note that abbreviations are only included if they'd be commonly recognized.)
Each metazones represent a set names that can be used across multiple TZ ids. There can be overrides by TZ id, such as the current:
<zone type="Europe/London">
<long>
<daylight>British Summer Time</daylight>
</long>
</zone>
<zone type="Europe/Dublin">
<long>
<daylight>Irish Standard Time</daylight>
</long>
</zone>
Both of these inherit
<standard>Greenwich Mean Time</standard>
So a current implementation, with no changes, will get for Europe/Dublin:
<standard>Greenwich Mean Time</standard>
<daylight>Irish Standard Time</daylight>
Different clients will use the data in different ways. The source for ICU, for example, reformats to a key-value map:
"meta:America_Eastern"{
ld{"Eastern Daylight Time"}
lg{"Eastern Time"}
ls{"Eastern Standard Time"}
sd{"EDT"}
sg{"ET"}
ss{"EST"}
}
The normal interpretation of "standard" and "daylight" keywords or equivalents is that:
standard_offset = 0
daylight_offset ≠ 0