Issue Summary

When trying to enter a value in a datetime field for the day that daylight saving starts in the user's selected timezone, the value shown in the field will be an hour later than what was selected.

e.g. When the user selects 6 AM on that day from the dropdown, the field value is saved as 7 AM.

This doesn't occur for the entire day, it appears to start at the hour that is 'skipped' (generally 2-3AM or 12-1AM depending on the timezone) and stops at a point later in the day. After that point, the time selected and the time saved in the field will match.

How long the problem continues varies for different timezones using DST:

• Europe/London - until 10AM
• Europe/Copenhagen - until 11AM
• Asia/Beirut - until 7AM
• US/Central - until 5PM
• Chile/Continental - Until 2PM
• America/Asuncion - Until 2PM

Australia and New Zealand timezones behave inconsistently with the other tested timezones and each other:

• Pacific/Auckland - The time entered will jump back an hour from what was selected, not forward, until after the time change at 3AM and then it behaves normally.
• Australia/Sydney - The time is saved exactly as entered, which also allows choosing a time that won't exist (between 2-3AM).

This doesn't seem to be a hemisphere issue, since Chile and Paraguay timezones above behave the same as the northern hemisphere if you select their change dates in September/October.

Steps to Reproduce

1. Set your timezone in user preferences to a timezone that observes daylight saving
2. In a datetime field, select 4:00 AM on the day that daylight savings begins for your timezone

Expected Results

The field shows 4:00 AM, as selected by the user.

Actual Results

The field shows 5:00 AM instead.

Workaround

The user can adjust their selection to get the value that they want in the field during that affected period, i.e. select 3:00 AM instead so the field saves the required 4:00 AM.