From 7b3d77ed3422612e6c7e288aab1ebdcbc9e59dbc Mon Sep 17 00:00:00 2001
From: Mustapha Zorgati <15628173+mustaphazorgati@users.noreply.github.com>
Date: Tue, 23 Feb 2021 10:58:41 +0100
Subject: [PATCH] updated README to describe new environment variable

---
 README.md | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 7a0e56c..feccadf 100644
--- a/README.md
+++ b/README.md
@@ -184,9 +184,18 @@ Only keep last a few days backup files in the storage system. Set to `0` to keep
 
 Default: `0`
 
+#### BACKUP_FILE_DATE_SUFFIX
+
+Each backup file is suffixed by default with `%Y%m%d`. If you back up your vault multiple times a day that suffix is not unique anymore.
+This environment variable allows you to append that date (`%Y%m%d${BACKUP_FILE_DATE_SUFFIX`) suffix in order to create a unique backup name. 
+
+Please use the [date man page](https://man7.org/linux/man-pages/man1/date.1.html) for the format notation.
+
+Default: ` `
+
 #### TIMEZONE
 
-You should set the available timezone name. Currently only used in mail.
+You should set the available timezone name. Currently only used in mail. The timezone information will also be used if you use `%Z` in `BACKUP_FILE_DATE_SUFFIX`.
 
 Here is timezone list at [wikipedia](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones).