Title: apply calculation automatically
Last modified: August 8, 2025

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# apply calculation automatically

 *  [knireis](https://wordpress.org/support/users/knireis/)
 * (@knireis)
 * [9 months, 3 weeks ago](https://wordpress.org/support/topic/apply-calculation-automatically/)
 * Hi, I created a new date calculation field with [start_lidmaatschap]+[#25_years]
   =[?year] as template field.
 * It works fine but only after resaving a participant. Is it possible to apply 
   this field automatically to all existing participants? Thanks

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Plugin Author [rolandbarker](https://wordpress.org/support/users/rolandbarker/)
 * (@rolandbarker)
 * [9 months, 3 weeks ago](https://wordpress.org/support/topic/apply-calculation-automatically/#post-18591397)
 * When you define or edit the template for the date calculation field, all the 
   records will be updated with the new calculation. This process happens in the
   background.
 * After making a change to the template, you should see all the records update 
   with the new calculation. You can try making a temporary change to the calculation
   template to test this. To get a more detailed view of what is going on, use the
   [plugin debugger](https://xnau.com/using-the-participants-database-debugging-log/)
   to see the result of the calculation on each record.
 * It’s important to note that if the record doesn’t contain the needed values for
   the calculation, no change will be made to that record.
 * It is possible that your server configuration isn’t allowing the background process
   to work. For example, this can happen with hosting that uses an aggressive cache
   on the “options” database table.
 *  Thread Starter [knireis](https://wordpress.org/support/users/knireis/)
 * (@knireis)
 * [9 months, 3 weeks ago](https://wordpress.org/support/topic/apply-calculation-automatically/#post-18591490)
 * Thanks for the reply. I resaved the participants and now a change in the template
   is reflected immediately, but initially the fields returned a 0 or were empty.
   Anyway it works now.
 * I noticed some strange behavior with a date calculation like [start_lidmaatschap]
   +[#25_years]=[?year],
 * When [start_lidmaatschap] is on first of january it calculates the year minus
   1, so 01-jan-2000 will return 2024, while 02-jan-2000 will return 2025. Any idea
   why that happens?
 *  Plugin Author [rolandbarker](https://wordpress.org/support/users/rolandbarker/)
 * (@rolandbarker)
 * [9 months, 3 weeks ago](https://wordpress.org/support/topic/apply-calculation-automatically/#post-18592213)
 * This can happen when there is a difference in time zone from the WP install and
   the web server. This article explains how you can deal with that: [Date Shifting and Other Timezone-related Issues in Participants Database](https://xnau.com/date-shifting-and-other-timezone-related-issues-in-participants-database/)

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘apply calculation automatically’ is closed to new replies.

 * ![](https://ps.w.org/participants-database/assets/icon-256x256.jpg?rev=1389807)
 * [Participants Database](https://wordpress.org/plugins/participants-database/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/participants-database/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/participants-database/)
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 * [Unresolved Topics](https://wordpress.org/support/plugin/participants-database/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/participants-database/reviews/)

 * 3 replies
 * 2 participants
 * Last reply from: [rolandbarker](https://wordpress.org/support/users/rolandbarker/)
 * Last activity: [9 months, 3 weeks ago](https://wordpress.org/support/topic/apply-calculation-automatically/#post-18592213)
 * Status: not resolved