How to get first day of the month in Oracle

 In Oracle, getting the first day of the month is very simple 

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✅ Basic Query

SELECT TRUNC(SYSDATE, 'MM') FROM dual;

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🔎 Explanation

• TRUNC(date, 'MM') → returns 1st day of that month

• Time will be 00:00:00

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🧪 Examples

🔹 Current month first day

SELECT TRUNC(SYSDATE, 'MM') FROM dual;

🔹 For a specific date

SELECT TRUNC(TO_DATE('24-MAR-2026','DD-MON-YYYY'), 'MM')
FROM dual;

👉 Output: 01-MAR-2026

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✅ First day of previous month

SELECT TRUNC(ADD_MONTHS(SYSDATE, -1), 'MM') FROM dual;

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✅ First day of next month

SELECT TRUNC(ADD_MONTHS(SYSDATE, 1), 'MM') FROM dual;

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🚀 Usage in WHERE clause

WHERE some_date >= TRUNC(SYSDATE, 'MM')

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