diff --git a/README.md b/README.md
index d330e54..fb648e3 100644
--- a/README.md
+++ b/README.md
@@ -633,6 +633,9 @@ Currently, the following substitutions will be made during new note creation:
 | `{{week}}` | week of the year | 46 |
 | `{{lastweek}}` | prior week of the year | 45 |
 | `{{nextweek}}` | next week of the year | 47 |
+| `{{isoweek}}` | week of the year in iso format | 2021-W46 |
+| `{{lastisoweek}}` | prior week of the year in iso format | 2021-W45 |
+| `{{nextisoweek}}` | next week of the year in iso format| 2021-W47 |
 | `{{year}}` | year | 2021 |
 
 As an example, this is my template for new notes:
diff --git a/lua/telekasten.lua b/lua/telekasten.lua
index cfe49fd..fcde40d 100644
--- a/lua/telekasten.lua
+++ b/lua/telekasten.lua
@@ -203,6 +203,7 @@ local function calenderinfo_today()
     local oneweek = 7 * oneday
     local date_format = "%Y-%m-%d"
     local week_format = "%V"
+    local isoweek_format = "%Y-W%V"
     local opts = {}
     opts.date = os.date(date_format)
     opts.yesterday = os.date(date_format, os.time() - oneday)
@@ -225,6 +226,9 @@ local function calenderinfo_today()
     opts.week = os.date(week_format)
     opts.lastweek = os.date(week_format, os.time() - oneweek)
     opts.nextweek = os.date(week_format, os.time() + oneweek)
+    opts.week = os.date(isoweek_format)
+    opts.lastisoweek = os.date(isoweek_format, os.time() - oneweek)
+    opts.nextisoweek = os.date(isoweek_format, os.time() + oneweek)
     opts.month = dinfo.month
     opts.year = dinfo.year
     opts.day = dinfo.day