IdentifyDaylightSavingsSundays

Problem Statement

To anchor a date to a specific day of the week - to either roll forward, or backward, to a specific day in the week.

Key Functions

• nextWeekDay() - Zoho Documentation.
• previousWeekDay() - Zoho Documentation.
• addWeek() - Zoho Documentation.
• addMonth() - Zoho Documentation.
• addYear() - Zoho Documentation.

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Business Use Case

Given a time and if it falls under the USA daylight savings, to either offset the time by 1 hour, or not.

USA daylight savings is applicable between:

• The second Sunday of March, to
• The first Sunday of November.

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Solution

Given the Business Use Case, using the nextWeekday() function will be sufficient as we will be performing the following steps:

graph TD
    A[Get today] --> B[Set to <b>First day</b> of March]
    B -->|startDate| C[Set to <b>following Sunday</b> in March<br>to get <b>First Sunday</b> of March]
    C --> D[Add <b>1 week</b> to startDate<br>to get <b>Second Sunday</b> of March]
    D -->|daylightSavingsStart| E(<b>END</b>)
    B --> F[Add 8 months]
    F --> G[Get <b>First day</b> of November]
    G -->|endDate|H[Set to following Sunday in November<br>to get <b>First Sunday</b> of November]
    H -->|daylightSavingsEnd| E

Loading

//To produce a date range starting from the 2nd Sunday in March to the 1st Sunday of November in the year.
startDate = (today.getYear().toString() + "-03-01").toDate();
endDate = startDate.addMonth(8);
daylightSavingsStart = startDate.nextWeekDay("Sunday").addWeek(1);
daylightSavingsEnd = endDate.nextWeekDay("Sunday");

When you run your info statements on daylightSavingsStart and daylightSavingsEnd, and compare them against startDate and endDate, you should see the the expected results.

info "Start of March: " + startDate + " (" + startDate.toString("E") + ")" + " | " + "Daylight Savings Start: " + daylightSavingsStart + " (" + daylightSavingsStart.toString("E") + ")";
info "Start of November: " + endDate + " (" + endDate.toString("E") + ")" + " | " + "Daylight Savings End: " + daylightSavingsEnd + " (" + daylightSavingsEnd.toString("E") + ")";