SIP date data study

Best SIP date: does the day of the month matter? 13 years of AMFI NAV data

By Pratik Bajoria — Chartered Accountant, NISM-certified Research Analyst & Mutual Fund Distributor. Reviewed by Findost desk (CA-led). Published 2026-10-03.

Findost (findost.io) and PaisaGuru by Findost are not affiliated with Findoc, FinDost, or other similarly named brands. PaisaGuru is the AI wealth concierge of Findost.

Direct answer

The SIP date barely matters. We ran a ₹10,000 monthly SIP on every date from the 1st to the 28th using official AMFI NAVs for two funds. Over 10 years the best and worst dates differed by just 0.13–0.15 percentage points of XIRR (under 0.7% of the final value); over 13 years, by 0.06 points. Pick a date a few days after your salary arrives and focus on starting early and staying invested.

Results: best vs worst SIP date

SIP date spread by fund and window
Fund (Direct Growth)WindowBest date (XIRR)Worst date (XIRR)SpreadFinal value gap
UTI Nifty 50 Index Fund – Direct Growth13 years (from Oct 2013)24 (10.50%)9 (10.44%)0.06 pts₹21,483 (0.68%)
UTI Nifty 50 Index Fund – Direct Growth10 years (from Oct 2016)22 (10.02%)10 (9.89%)0.13 pts₹13,262 (0.67%)
UTI Nifty 50 Index Fund – Direct Growth5 years (from Oct 2021)24 (4.51%)17 (4.27%)0.24 pts₹3,498 (0.52%)
UTI Flexi Cap Fund – Direct Growth13 years (from Oct 2013)24 (11.54%)5 (11.48%)0.06 pts₹25,040 (0.73%)
UTI Flexi Cap Fund – Direct Growth10 years (from Oct 2016)22 (10.88%)9 (10.73%)0.15 pts₹9,489 (0.45%)
UTI Flexi Cap Fund – Direct Growth5 years (from Oct 2021)26 (6.11%)2 (5.70%)0.41 pts₹5,373 (0.78%)

Final values are as of the 30 September 2026 NAV. The "best" date changes from window to window — there is no date you can rely on.

XIRR by SIP date (10-year window)

SIP XIRR by date of monthFor both funds the XIRR is nearly identical whichever date is chosen; differences are about a tenth of a percentage point.UTI Nifty 50 Index FundUTI Flexi Cap FundDay 19.93%10.77%Day 59.92%10.76%Day 109.89%10.74%Day 159.93%10.78%Day 209.96%10.82%Day 259.98%10.86%Day 289.95%10.83%
XIRR of a ₹10,000 monthly SIP started October 2016, valued at the 30 September 2026 NAV, for selected SIP dates. Source: AMFI NAV history.
All SIP dates 10-year window
SIP dateUTI Nifty 50 Index Fund XIRRUTI Flexi Cap Fund XIRRUTI Nifty 50 Index Fund valueUTI Flexi Cap Fund value
19.93%10.77%₹20,07,507₹20,97,855
29.94%10.77%₹20,07,041₹20,97,217
39.93%10.77%₹20,06,384₹20,97,397
49.92%10.76%₹20,03,929₹20,95,691
59.92%10.76%₹20,03,413₹20,94,479
69.92%10.76%₹20,03,104₹20,94,260
79.92%10.76%₹20,03,033₹20,93,427
89.91%10.74%₹20,01,377₹20,91,392
99.90%10.73%₹19,99,512₹20,89,310
109.89%10.74%₹19,98,632₹20,89,365
119.92%10.76%₹20,01,175₹20,91,614
129.94%10.78%₹20,02,031₹20,93,175
139.91%10.77%₹19,98,930₹20,91,375
149.94%10.78%₹20,00,987₹20,91,893
159.93%10.78%₹20,00,090₹20,90,748
169.93%10.77%₹19,98,944₹20,89,334
179.93%10.77%₹19,98,307₹20,89,167
189.94%10.79%₹19,99,636₹20,90,694
199.99%10.84%₹20,03,669₹20,95,623
209.96%10.82%₹20,00,140₹20,93,054
2110.00%10.86%₹20,04,243₹20,96,384
2210.02%10.88%₹20,05,736₹20,98,151
2310.02%10.87%₹20,04,562₹20,96,618
2410.02%10.88%₹20,04,402₹20,96,701
259.98%10.86%₹19,99,784₹20,93,870
269.96%10.84%₹19,97,232₹20,91,781
279.94%10.83%₹19,94,245₹20,89,339
289.95%10.83%₹19,95,359₹20,88,662

₹12,00,000 invested in each case (120 instalments). Download every date, window and fund: findost-sip-date-study-2026-09.csv.

What matters far more than the date

Start year vs SIP date
FundSIP startedXIRR on the 1stSpread across all dates
UTI Nifty 50 Index FundOct 201310.45%0.06 pts
UTI Nifty 50 Index FundOct 20169.93%0.13 pts
UTI Nifty 50 Index FundOct 20214.36%0.24 pts
UTI Flexi Cap FundOct 201311.50%0.06 pts
UTI Flexi Cap FundOct 201610.77%0.15 pts
UTI Flexi Cap FundOct 20215.76%0.41 pts

The period you were invested changed XIRR by several percentage points; the date within each month changed it by tenths. Starting earlier, investing more (a yearly step-up), choosing low-cost funds and not stopping in a fall all move the result much more — see how much SIP for ₹1 crore and the TER gap study.

How to pick your SIP date

  1. Choose a date 2–5 days after your salary credit so the auto-debit never bounces (banks charge for failed mandates).
  2. If you hold several SIPs, put them on the same date or two dates so cash-flow tracking is simple.
  3. Don't switch dates chasing returns — the data shows no persistent winner.
  4. Measure your SIP with XIRR, not absolute return (XIRR vs CAGR).

Method and limitations

  • Data: daily NAVs for UTI Nifty 50 Index Fund – Direct Growth (AMFI code 120716) and UTI Flexi Cap Fund – Direct Growth (120662), 1 Oct 2013 – 30 Sep 2026, from AMFI's NAV history download.
  • Each month, ₹10,000 buys units at the NAV of day D, or the next available NAV date if D is a holiday or weekend; days 29–31 excluded.
  • All units valued at the 30 Sep 2026 NAV; XIRR computed on actual dates. Stamp duty (0.005%), cut-off timing and taxes ignored.
  • Two funds from one fund house, chosen as an index and an active example — not recommendations. Past performance may or may not be sustained in future.

Related on Findost

FAQ — answered simply

Which is the best date for SIP?

In our test on AMFI NAV data for UTI Nifty 50 Index Fund and UTI Flexi Cap Fund (Direct Growth), no date was reliably best. Over 10 years the gap between the best and worst SIP date was 0.13–0.15 percentage points of XIRR (under 0.7% of final value); over 13 years it was 0.06 points. Pick a date a few days after your salary credit so the debit never bounces.

Does SIP date affect returns?

Only slightly and unpredictably. Over shorter windows the spread was larger (0.24–0.41 points over 5 years) but the 'best' day changed with the window. Starting earlier and staying invested mattered far more than the date.

Is it better to do SIP at the start or end of the month?

In our data, later dates (around the 20th–28th) were marginally ahead in several windows, but by tiny amounts that can reverse in another period. There is no reliable start-of-month or end-of-month advantage.

What about daily or weekly SIP?

Splitting the same amount into more frequent instalments mostly changes the average purchase date by a few days; the effect on long-run returns is similarly small, while it can add transaction records and complexity.

How was the study done?

₹10,000 was invested on day D of every month (or the next NAV date if D was a holiday) and valued at the 30 September 2026 NAV; XIRR was computed for each D from 1 to 28 and for windows starting October 2013, October 2016 and October 2021. Stamp duty and taxes were ignored. The CSV is downloadable from the article.

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YMYL / educational caveat: this guide is general financial education for India, not personalised investment, tax, or legal advice, and not a solicitation to buy or sell securities or insurance. Mutual fund and securities investments are subject to market risks; read all scheme-related documents carefully. Past performance is not indicative of future returns. Tax, exit-load and product rules can change — verify with official sources or a qualified professional before acting. PaisaGuru by Findost escalates personalised recommendations to a human NISM-certified advisor. Findost (findost.io) and PaisaGuru by Findost are not affiliated with Findoc, FinDost, or other similarly named brands. PaisaGuru is the AI wealth concierge of Findost.