1507.Reformat Date

Link: 1507. Reformat Date - Easy

Question

Restate the problem

We’re given a date string in the format “Day Month Year”, like "20th Oct 2052".
We need to convert it to the standardized numeric format “YYYY-MM-DD”, where the month is a two-digit number and the day is two digits (with leading zeros if needed).

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Method 1
Method 2 - Hashmap + split + slicing

Method

Approach

• For this problem, I first split the input string into three parts: day, month, and year.
• For the day, I remove the suffix like st/nd/rd/th and keep only the digits, then zero-pad it to two digits.
• For the month, I use a hash map to convert the month abbreviation (e.g., Jan, Feb) into a two-digit number.
• The year stays the same.
• Finally, I concatenate them in the format YYYY-MM-DD.

Complexity

• Time complexity: O(n)
  • split: O(n)
• Space complexity: O(n)

Edge Case

Code

class Solution:
    def reformatDate(self, date: str) -> str:
        day, month, year = date.split(" ")
 
        dic = {
            "Jan": '01', "Feb": '02', "Mar": '03', 
            "Apr": '04', "May": '05', "Jun": '06', 
            "Jul": '07', "Aug": '08', "Sep": '09', 
            "Oct": '10', "Nov": '11', "Dec":'12'}
            
        dd = day[:-2].zfill(2)
        
        return year + "-" + dic[month] + "-" + dd

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History

Jan-24-2026 Solved

Jan-19-2026 hinted don’t know zfill