How to set timestamp to aws region timezone for aws lambda python code

Question

in my python lambda code that scans dynamodb based on primary key as 'deviceId' & sortkey timestamp( which is in YYYY-MM-DD HH:MN:SS format) , i need to scan every for last 15min data (from time now). I am in Mumbai region (ap-south-1), how do I set local timezone in my following lambda code. since it is picking default utc datetime.The lambda ideally has to scan & if return count >= 10 then thermostat+5 .

import boto3
import math
import json
import time
from datetime import datetime,timedelta
from dateutil.tz import tzlocal
from boto3.dynamodb.conditions import Key, Attr

client = boto3.client('dynamodb')
dynamodb = boto3.resource('dynamodb')

def lambda_handler(event, context):

    #table_name= "thermostat_dynamo"
    table_name= "newsensor"
    Primary_Column_Name = 'deviceId'
    table = dynamodb.Table(table_name)
    #key_param = "thermostat"
    #thermostatVal = table.get_item(Key={key_param:event[key_param]}) ## get record from dynamodb for this sensor
    thermostatVal= 77
    #now = datetime.now()
    now = datetime.now(tzlocal())
    fifteen_min_ago =  now - timedelta(seconds=900)
    now = now.strftime('%F %T')
    fifteen_min_ago = fifteen_min_ago.strftime('%F %T')

    fe = Key('timeStamp').between(fifteen_min_ago,now);
    response = table.scan(FilterExpression=fe & Attr('temperature').lt(thermostatVal))

    if response['Count'] == 10:
    #return thermostatVal+5 
        thermonew = thermostatVal + 5
        tosensor = '{"thermostat":'+'"%s"}' %thermonew
        print(tosensor)
        #response = client.publish(topic="updatehomesensor", qos=1, payload=tosensor)
        return

    elif response['Count'] < 10:
        #tosensor = '{"thermostat":'+'"%s"}' %thermostatVal
        print('{"thermostat":'+'"%s"}' %thermostatVal)
        #response = client.publish(topic="updatehomesensor", qos=1, payload=tosensor)
        return

Ketav Sharma · Accepted Answer · 2020-11-09 11:11:55Z

27

All Lambda instances are set to UTC timezone. Incase you want to change that behavior you need to update environment variable.

Detailed document is below which mentions TZ as Reserved environment variable https://docs.aws.amazon.com/lambda/latest/dg/configuration-envvars.html.

So in your case for example you want to setup lambda to use IST [ Indian Standard Timezone ]. You need to go through following steps.

In configuration tab of function scroll down to environment variables section.
Click Edit and add variable TZ with value Asia/Calcutta [ For IST ].

It should look like below

After saving the environment variable your environment will use timezone mentioned in the TZ variable.

answered Nov 9, 2020 at 11:11

Ketav Sharma

5095 silver badges9 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

PaulJNewell Over a year ago

Does this actually work? The term 'reserved' in this context seems to mean that you cannot change it in this way.

Ketav Sharma Over a year ago

Yes it works and i am using it. Reserved means it can only be used for its intended purpose its not constant so that it cant be changed.

Raymond Chen Over a year ago

This works for me! And for those who are looking for your timezone value to put here, check out this link en.wikipedia.org/wiki/List_of_tz_database_time_zones

David Winiecki · Accepted Answer · 2024-08-09 19:34:45Z

0

As far as I can tell the Intl namespace of the JavaScript standard library is now fully(?) supported and works well for formatting date and time strings that include timezone:

console.log(new Intl.DateTimeFormat(
    /*locales=*/undefined,  // use default, probably en-US
    {
        timeZone: 'US/Pacific',
        timeStyle: 'long',
    }
).format(new Date));
// '11:55:34 AM PDT'

answered Aug 9, 2024 at 19:34

David Winiecki

4,2432 gold badges39 silver badges42 bronze badges

Collectives™ on Stack Overflow

How to set timestamp to aws region timezone for aws lambda python code

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related