Does the Platform Handle DST Time Shifting

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Yes, our platform automatically handles Daylight Saving Time (DST) transitions. When the time changes in spring or fall, the platform ensures proper time conversion, and for teachers scheduling lessons, provides an intelligent warning system to prevent student time shifts.

How It Works

All lesson times are stored in UTC (Coordinated Universal Time) in our database. When you view a lesson, the platform automatically converts it to your local timezone, taking into account whether DST is active on that specific date.

Key Principle: The person whose timezone has DST will always see their lesson time stay constant. The person whose timezone does NOT have DST will see the time shift by one hour after the DST transition.

DST Warning for Teachers (New Feature)

When teachers schedule lessons that cross a DST transition date, the platform now displays an intelligent warning dialog. This prevents accidentally shifting the student's lesson time.

The warning appears when:

• Teacher is scheduling one or more lessons
• Any lesson dates fall after a DST transition (either teacher's or student's timezone)
• The timezone offset difference between teacher and student changes on those dates

The warning shows:

• How many lessons out of the total are affected by DST
• Whether times need to shift "earlier" or "later" to keep the student's time constant
• Three options to choose from

Your Options:

1. "Shift 1hr earlier/later (Recommended)" - Adjusts the teacher's scheduled time by 1 hour for affected lessons only, keeping the student's time constant. This is the default and recommended option.
2. "Keep current time" - Keeps the teacher's time constant, which means the student's time will shift by 1 hour for lessons after the DST transition.
3. "Cancel" - Cancel the scheduling operation to reconsider the timing.

Example: A California teacher schedules 100 weekly lessons starting Nov 1 for a Moscow student (Russia has no DST). The warning shows: "Important: 37 of your scheduled 100 lessons fall within or after a DST transition period. To keep the student's lesson time constant, would you like to shift these lessons 1 hour earlier?" The teacher can choose to shift their time earlier (recommended) or keep their time constant (student shifts).

Behavior Summary Table

ScenarioWho Has DSTTime Stays Constant ForTime Shifts ForTeacher schedulesTeacherTeacherStudent (if no DST)Student schedulesStudentStudentTeacher (if no DST)Both have DST (same dates)BothBothNeitherBoth have DST (different dates)BothPerson who transitions firstPerson who transitions later (temporarily)Neither has DSTNeitherBothNeither

Example 1: One Party Has DST, One Doesn't

Setup:

• Teacher: New York City (America/New_York - has DST)
• Student: Arizona (America/Phoenix - no DST)
• DST change date: March 9, 2025 at 2:00 AM

Teacher books recurring lessons at 4:00 PM every Friday:

What this means: The teacher always sees 4:00 PM (constant), while the student in Arizona sees the time shift from 2:00 PM to 1:00 PM after the DST transition.

Example 2: Both Have DST, But Different Transition Dates

Setup:

• Teacher: New York City (America/New_York - DST changes March 9)
• Student: Paris (Europe/Paris - DST changes March 30)
• Teacher books recurring lessons at 4:00 PM EDT

What happens:

Key Insight: Between March 9-30, the student in Paris sees lessons shift from 10:00 PM to 9:00 PM because:

1. NYC transitioned to DST on March 9 (teacher's time stayed 4:00 PM)
2. Paris hadn't transitioned yet (still CET)
3. After Paris transitions on March 30, times realign to the original difference

This is the most confusing scenario! When both parties have DST but different transition dates, expect a temporary 1-hour shift during the gap period.

Best Practices

To avoid confusion:

1. Use the DST warning feature: When teachers schedule lessons, the platform automatically detects DST mismatches and offers to adjust times. The recommended option always keeps the student's time constant.
2. If one party does NOT have DST (like Arizona): The platform will detect this and warn teachers during scheduling. Teachers can choose to shift their time to keep the student's time constant.
3. If both have DST with same transition dates (e.g., both in US): No warning needed - both see constant times.
4. If both have DST with DIFFERENT transition dates (e.g., US & Europe): ⚠️ Most confusing scenario! The platform will detect the temporary mismatch. Teachers can use the DST warning to adjust affected lessons, or communicate and reschedule after both transitions complete.
5. Always communicate with the other party about DST transitions, especially if one party doesn't observe DST or if DST dates differ between regions.

DST Transition Dates

North America:

• Starts DST: Second Sunday of March (March 9, 2025, at 2:00 AM local time)
• Ends DST: First Sunday of November (November 2, 2025, at 2:00 AM local time)
• Change: Clocks spring forward 1 hour in March, fall back 1 hour in November

Western Europe:

• Starts DST: Last Sunday of March (March 30, 2025, at 1:00 AM UTC)
• Ends DST: Last Sunday of October (October 26, 2025, at 1:00 AM UTC)
• Change: Clocks spring forward 1 hour in March, fall back 1 hour in October

Gap Period: US transitions ~3 weeks before Europe in spring, ~1 week before in fall

Note: These dates follow the same pattern every year. The platform automatically handles all timezone conversions and DST transitions using PHP's built-in timezone database.