Bug: when period=3M start date falls on a Sunday, IRR % is wrong

[wilsonleong]

Considerations:

• what if it falls on to a HK holiday or US holiday where there is no market data (for latest valuation calculation) for either HK or US market?

[wilsonleong]

Incorrect starting cashflow value in IRR calculation on market holidays

For IRR calculation, when date range start date has no market data (weekend or market holiday), the "previous valuation" as of start date becomes 0 incorrectly, causing error in the IRR calculation.

Tactical fix by adjusting start date as Friday when it falls onto a Saturday or Sunday.

This still does not adjust for market holidays in HK or US. Proper fix should check for market holidays and try to get valuations for the previous business day.