AST to IST Converter

Category: Time Zone Converters

- July 10, 2025

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Atlantic Standard Time (AST)

UTC-4 • Halifax, San Juan, Bermuda

Conversion Settings

Configure your timezone conversion preferences

Auto Convert

Daylight Saving Aware

Show UTC Offset

Show Seconds

India Standard Time (IST)

UTC+5:30 • Mumbai, Delhi, Bangalore

--:--:--

Select a time to convert

Time Difference: --

UTC Offset (AST/ADT): -4

UTC Offset (IST): +5:30

DST Status: --

AST/ADT Time: --

IST Time: --

Time Format:

Current AST/ADT: --:--:--

Current IST: --:--:--

🌍 AST is UTC-4 (winter) / ADT is UTC-3 (summer). IST is UTC+5:30 year-round. Time difference varies between 8.5-9.5 hours.

AST/ADT to IST Conversion Guide

What is AST/ADT to IST Conversion?

AST/ADT to IST conversion helps you translate time between Atlantic Time and India Standard Time. AST (UTC-4) is used in winter and ADT (UTC-3) in summer in Atlantic Canada and Caribbean regions. IST (UTC+5:30) is used year-round across all of India without daylight saving changes.

Time Zone Information

Atlantic Standard Time (AST): UTC-4, used in winter (November to March) in Atlantic Canada and Caribbean.

Atlantic Daylight Time (ADT): UTC-3, used in summer (March to November) when daylight saving is observed.

India Standard Time (IST): UTC+5:30, used year-round across all of India with no regional variations.

Time Difference: IST is 9.5 hours ahead of AST and 8.5 hours ahead of ADT.

Daylight Saving Time Impact

AST Period: November to March - IST is 9.5 hours ahead

ADT Period: March to November - IST is 8.5 hours ahead

IST Consistency: Never changes, providing stable reference for Indian business hours

Common Conversion Examples

Winter Morning Hours (AST)

AST 8:00 AM → IST 5:30 PM

AST 10:00 AM → IST 7:30 PM

9.5-hour difference during standard time

Summer Morning Hours (ADT)

ADT 8:00 AM → IST 4:30 PM

ADT 10:00 AM → IST 6:30 PM

8.5-hour difference during daylight time

Evening Atlantic to Morning India

AST 11:00 PM → IST 8:30 AM (next day)

ADT 11:00 PM → IST 7:30 AM (next day)

Date changes due to large time difference

Late Night Transitions

AST 2:00 AM → IST 11:30 AM

ADT 2:00 AM → IST 10:30 AM

Early morning Atlantic to late morning India

Conversion Tips & Best Practices

• IST is always significantly ahead of Atlantic Time - add 8.5-9.5 hours depending on season

• During AST period (winter): add 9.5 hours to AST to get IST

• During ADT period (summer): add 8.5 hours to ADT to get IST

• AST/ADT covers Atlantic Canada, Caribbean islands, Puerto Rico, and US Virgin Islands

• Best meeting times: AST/ADT 8-10 AM (IST 4:30-7:30 PM) for business overlap

• Late evening Atlantic time often converts to next morning in India

Convert Time Between India and the Atlantic Coast

Whether you're scheduling a meeting across continents or planning a call with family on the other side of the world, aligning time zones can be a headache. This tool makes it easier by converting between Atlantic Standard Time (AST/ADT) and India Standard Time (IST) with clarity and speed. Here’s a quick visual breakdown of countries in each zone:

Atlantic Standard/Daylight Time (AST/ADT) UTC-4 / UTC-3	India Standard Time (IST) UTC+5:30
🇧🇲 Bermuda 🇨🇦 Canada (Nova Scotia, New Brunswick, Prince Edward Island) 🇩🇲 Dominica 🇬🇩 Grenada 🇬🇵 Guadeloupe 🇲🇶 Martinique 🇲🇸 Montserrat 🇰🇳 Saint Kitts and Nevis 🇱🇨 Saint Lucia 🇻🇨 Saint Vincent and the Grenadines 🇧🇶 Sint Eustatius 🇧🇶 Saba 🇧🇶 Saint Barthélemy 🇹🇹 Trinidad and Tobago 🇵🇷 Puerto Rico 🇻🇮 US Virgin Islands	🇮🇳 India 🇱🇰 Sri Lanka

Atlantic Standard/Daylight Time (AST/ADT)
UTC-4 / UTC-3

India Standard Time (IST)
UTC+5:30

🇧🇲 Bermuda

🇨🇦 Canada (Nova Scotia, New Brunswick, Prince Edward Island)

🇩🇲 Dominica

🇬🇩 Grenada

🇬🇵 Guadeloupe

🇲🇶 Martinique

🇲🇸 Montserrat

🇰🇳 Saint Kitts and Nevis

🇱🇨 Saint Lucia

🇻🇨 Saint Vincent and the Grenadines

🇧🇶 Sint Eustatius

🇧🇶 Saba

🇧🇶 Saint Barthélemy

🇹🇹 Trinidad and Tobago

🇵🇷 Puerto Rico

🇻🇮 US Virgin Islands

🇮🇳 India

🇱🇰 Sri Lanka

A tool built to make timing simpler

This calculator converts time between AST/ADT and IST with just a few clicks. It's ideal for teams with members in India and the Atlantic coast, remote workers managing global meetings, or even travelers coordinating across time zones. Whether it’s a business call between Halifax and Bangalore or catching up with family from San Juan to Mumbai, you’ll see the exact hour and minute difference right away.

Pick your time, set your zone, and get results

Start by entering your time

Select the date and time you want to convert. The tool supports both 12-hour and 24-hour formats, with or without seconds. You can even press the “Now” button to pull the current local time from either AST/ADT or IST depending on your selection.

Choose your input timezone

Pick between Atlantic Standard Time or India Standard Time using the dropdown. The title and location details above the input box will adjust accordingly. This helps you make sure you're working with the right side of the conversion.

Press Convert or Let It Happen Automatically

By default, the “Auto Convert” option is turned on, meaning your changes trigger immediate results. If you turn that off, you’ll need to click the Convert button manually. Either way, you’ll get a precise translation of your input time to the other zone.

Want to switch directions?

Use the “Swap” button to flip input and output zones. The tool also switches the titles and labels so you don’t get confused about which time you're converting.

Extra toggles that give you control

Account for daylight time

If you're working with locations that observe daylight saving, keep “Daylight Saving Aware” checked. That ensures the converter adjusts between AST and ADT automatically based on the date selected. If you turn it off, the tool will ignore DST and stick to standard UTC offsets.

See the offset if needed

Toggle “Show UTC Offset” to display exact UTC differences, such as -4 or +5:30. This is helpful for those who work with teams in other offsets or use UTC as a reference.

Toggle seconds and format

If you want more precision, “Show Seconds” keeps them visible in your results. And if you prefer military-style time, the “12 Hour / 24 Hour” button will switch the format instantly.

Where this tool makes life easier

Suppose you're part of a development team based in Chennai, India, collaborating with a partner firm in Nova Scotia, Canada. You’re planning daily check-ins at 9:00 AM AST. Instead of guessing or Googling time zones every time, just enter 9:00 AM on the calendar, and the tool tells you it's 6:30 PM IST. No mental math, no confusion.

Small features that solve big headaches

Live clocks

The current time in both Atlantic and Indian time zones updates live, right on the page. This is perfect for checking your local time against the other zone at a glance.

Smart defaults

The converter auto-fills your current Atlantic time when the page loads. It also remembers your preference for DST awareness, seconds, and format so you don’t have to redo settings every time.

Keyboard shortcuts built-in

Use keyboard keys to speed things up. Press N for “Now,” S to swap, R to reset, and F to toggle the format. No clicking required.

Skip the guesswork, make every meeting on time

This AST to IST time converter strips out the hassle and gives you a clear view of what time it really is across the world. Whether you're managing a team or planning a call, it’s all about clarity. Forget timezone confusion and focus on the work.