# Seasonal trend loess (STL) decomposition around holidays

I am seasonally adjusting a weekly transaction time-series. The seasonal adjustment works great, except for on and around closed days. At and around these points there are serious errors. What is the proper way to decompose a time series for these localized closed days?

I can think of a couple options

1. on closed days the seasonal adjustment = the observation
2. on closed days the seasonal adjustment = trend
3. remove closed days and days around closed days

For more information, I am using decompose(type = "multiplicative"). I have tried additive, but had much worse performance.

• Please edit your question to spell out the abbreviation "STL" at its first use, or simply use the full form instead of an abbreviation. – Kodiologist Apr 30 '18 at 14:44