The Indian stock exchange opens at 09.15, so when requesting the history of '^NSEI' by 30 minute intervals, the resampling will not include the first 15 minutes of the day. Note: This only happens to 30 min intervals because of the specific handling of 30 min.
Solution
@ivan23kor created a pull request some time ago to solve the issue, but the solution is now outdated.
I propose a solution that checks what time the exchange opens and adds that to the offset that ivan suggested:
Fix 30min interval of ^NSEI and indian exchange
Regarding #1436 and #1447
Summary
The Indian stock exchange opens at 09.15, so when requesting the history of '^NSEI' by 30 minute intervals, the resampling will not include the first 15 minutes of the day. Note: This only happens to 30 min intervals because of the specific handling of 30 min.
Solution
@ivan23kor created a pull request some time ago to solve the issue, but the solution is now outdated.
I propose a solution that checks what time the exchange opens and adds that to the offset that ivan suggested: