I have been tasked with producing an forecast of daily volumes for 2 weeks before and 2 weeks after holiday dates / specific event dates (e.g. Reviewing the 2 weeks before and after Easter Monday (14/03/2016 this year)).
We have no WFM system, it needs to be Excel driven. I have 7 months of 2014 daily volumes (Jan-July), and then May onward data for 2015/2016. So I realise I am missing a good chunk of required data.
What would be the best way to approach this? A majority of what I've read online is about forecasting month, day, interval volumes seasonally using time series analysis.
I've worked something up, which to simplify, takes the date of the holiday minus e.g. 14 (for the 14th day prior to the event) from historical data and works out the difference between that days volume and a regular equivalent days volume in the same month to find a percentage uplift/drop that can be applied to my future normal day projection. This is repeated for all days within the two weeks before and after the holiday date.
Due to the fact that holidays fall on different days and dates, I'm not sure at all if this is at all accurate, or if there is a better way to do this.
I'd be grateful for any advice or suggestions on this. Can you think of a better way to do this, major floors in the logic, anything that can assist me towards producing what my people want from me.
Many thanks in advance guys.