gets confused about US summer time change date

generated today:

anarcat@angela:~(master)$ undertime 
╔════════════╦════════════╦═══════╦══════════════╗
║ US/Pacific ║ US/Eastern ║  UTC  ║ Europe/Paris ║
╠════════════╬════════════╬═══════╬══════════════╣
║   20:00    ║   23:00    ║ 04:00 ║    05:00     ║
║   21:00    ║   00:00    ║ 05:00 ║    06:00     ║
║   22:00    ║   01:00    ║ 06:00 ║    07:00     ║
║   23:00    ║   02:00    ║ 07:00 ║    08:00     ║
║   00:00    ║   03:00    ║ 08:00 ║     09:00    ║
║   01:00    ║   04:00    ║ 09:00 ║     10:00    ║
║   02:00    ║   05:00    ║ 10:00 ║     11:00    ║
║   03:00    ║   06:00    ║ 11:00 ║     12:00    ║
║   04:00    ║   07:00    ║ 12:00 ║     13:00    ║
║   05:00    ║   08:00    ║ 13:00 ║     14:00    ║
║   06:00    ║    09:00   ║ 14:00 ║     15:00    ║
║   07:00    ║    10:00   ║ 15:00 ║     16:00    ║
║   08:00    ║    11:00   ║ 16:00 ║     17:00    ║
║    09:00   ║    12:00   ║ 17:00 ║    18:00     ║
║    10:00   ║    13:00   ║ 18:00 ║    19:00     ║
║    11:00   ║    14:00   ║ 19:00 ║    20:00     ║
║    12:00   ║    15:00   ║ 20:00 ║    21:00     ║
║    13:00   ║    16:00   ║ 21:00 ║    22:00     ║
║    14:00   ║    17:00   ║ 22:00 ║    23:00     ║
║    15:00   ║   18:00    ║ 23:00 ║    00:00     ║
║    16:00   ║   19:00    ║ 00:00 ║    01:00     ║
║    17:00   ║   20:00    ║ 01:00 ║    02:00     ║
║   18:00    ║   21:00    ║ 02:00 ║    03:00     ║
║   19:08    ║   22:08    ║ 02:08 ║    03:08     ║
║   19:00    ║   22:00    ║ 03:00 ║    04:00     ║
╚════════════╩════════════╩═══════╩══════════════╝
Table generated for time: 2020-03-08 22:08:00-04:00

Most times in the US/Eastern column are wrong: they are using the "EST" and not "EDT" time, except the current time which is properly formatted (it is 22:08 EDT, UTC-4, so 02:08 UTC).

This occurs when I use the following configuration:

timezones: ['US/Pacific', 'US/Eastern', 'UTC', 'Europe/Paris']
default_zone: false

With --default-zone, the problem doesn't occur:

anarcat@angela:~(master)$ undertime  --default-zone
WARNING: skipping zone US/Eastern with existing offset -4:00:00
╔═══════╦════════════╦═══════╦══════════════╗
║  EDT  ║ US/Pacific ║  UTC  ║ Europe/Paris ║
╠═══════╬════════════╬═══════╬══════════════╣
║ 00:00 ║   20:00    ║ 04:00 ║    05:00     ║
║ 01:00 ║   21:00    ║ 05:00 ║    06:00     ║
║ 02:00 ║   22:00    ║ 06:00 ║    07:00     ║
║ 03:00 ║   23:00    ║ 07:00 ║    08:00     ║
║ 04:00 ║   00:00    ║ 08:00 ║     09:00    ║
║ 05:00 ║   01:00    ║ 09:00 ║     10:00    ║
║ 06:00 ║   02:00    ║ 10:00 ║     11:00    ║
║ 07:00 ║   03:00    ║ 11:00 ║     12:00    ║
║ 08:00 ║   04:00    ║ 12:00 ║     13:00    ║
║ 09:00 ║   05:00    ║ 13:00 ║     14:00    ║
║ 10:00 ║   06:00    ║ 14:00 ║     15:00    ║
║ 11:00 ║   07:00    ║ 15:00 ║     16:00    ║
║ 12:00 ║   08:00    ║ 16:00 ║     17:00    ║
║ 13:00 ║    09:00   ║ 17:00 ║    18:00     ║
║ 14:00 ║    10:00   ║ 18:00 ║    19:00     ║
║ 15:00 ║    11:00   ║ 19:00 ║    20:00     ║
║ 16:00 ║    12:00   ║ 20:00 ║    21:00     ║
║ 17:00 ║    13:00   ║ 21:00 ║    22:00     ║
║ 18:00 ║    14:00   ║ 22:00 ║    23:00     ║
║ 19:00 ║    15:00   ║ 23:00 ║    00:00     ║
║ 20:00 ║    16:00   ║ 00:00 ║    01:00     ║
║ 21:00 ║    17:00   ║ 01:00 ║    02:00     ║
║ 22:00 ║   18:00    ║ 02:00 ║    03:00     ║
║ 22:16 ║   19:16    ║ 02:16 ║    03:16     ║
║ 23:00 ║   19:00    ║ 03:00 ║    04:00     ║
╚═══════╩════════════╩═══════╩══════════════╝
Table generated for time: 2020-03-08 22:16:00-04:00

which is very strange because it explicitely says it has the same offset...

Of course this had to happen after I wrote 538ab723