OSM supports really complex opening times, apparently.

This node, a roof-top bar in Stratford, London is opening on the 20th of April. The following are the opening times per their website:

• April 20th to April 30th : Thursdays to Fridays 5pm- 11pm, Saturdays-Sundays 12-11pm
• May 1st- May 14th: Wednesdays to Fridays 5pm- 11pm, Saturdays-Sundays 12-11pm, Bank Holidays 12-11pm
• May 15th- end of September: Tuesdays to Fridays 5pm- 11pm, Saturdays-Sundays 12-11pm, Bank Holidays 12-11pm

The opening_time value I came up with is this:

Apr 20-30 Sa-Su 12:00-23:00; May-Sep Sa-Su 12:00-23:00; Apr 20-30 Th-Fr 17:00-23:00; May 01-14 We-Fr 17:00-23:00; May 15-31 Tu-Fr 17:00-23:00; Jun-Sep Tu-Fr 17:00-23:00; Oct-Dec off; Apr 20-30 PH 12:00-23:00; May-Sep PH 12:00-23:00

It also helped that there exists a handy tool that can visualise complex opening_time values.

I am looking forward to seeing how OSMAnd handles this when it eventually gets the updated node.