Patch submitted upstream: https://github.com/robotframework/robotframework/pull/4286.

diff --git a/atest/robot/standard_libraries/operating_system/modified_time.robot b/atest/robot/standard_libraries/operating_system/modified_time.robot
index d144ffd34..c7681e61d 100644
--- a/atest/robot/standard_libraries/operating_system/modified_time.robot
+++ b/atest/robot/standard_libraries/operating_system/modified_time.robot
@@ -8,7 +8,7 @@ ${TESTFILE}       %{TEMPDIR}${/}robot-os-tests${/}f1.txt
 *** Test Cases ***
 Get Modified Time As Timestamp
     ${tc} =    Check Test Case    ${TESTNAME}
-    Should Match Regexp    ${tc.kws[0].msgs[0].message}    Last modified time of '<a href=.*</a>' is 20\\d\\d-\\d\\d-\\d\\d \\d\\d:\\d\\d:\\d\\d
+    Should Match Regexp    ${tc.kws[0].msgs[0].message}    Last modified time of '<a href=.*</a>' is \\d\\d\\d\\d-\\d\\d-\\d\\d \\d\\d:\\d\\d:\\d\\d
 
 Get Modified Time As Seconds After Epoch
     ${tc} =    Check Test Case    ${TESTNAME}
diff --git a/atest/testdata/standard_libraries/builtin/get_time.robot b/atest/testdata/standard_libraries/builtin/get_time.robot
index 9847d8c42..24ce732ca 100644
--- a/atest/testdata/standard_libraries/builtin/get_time.robot
+++ b/atest/testdata/standard_libraries/builtin/get_time.robot
@@ -11,18 +11,18 @@ Get Time As Timestamp
 
 Get Time As Seconds After Epoch
     ${time} =    Get Time    epoch
-    Should Be True    1000000000 < ${time} < 2000000000
+    Should Be True    0 < ${time}
 
 Get Time As Parts
     @{time} =    Get Time    year, month, day, hour, min, sec
-    Should Be True    2000 < ${time}[0] < 2100
+    Should Match Regexp    ${time}[0]    \\d{4}
     Should Be True    1 <= int('${time}[1]') <= 12
     Should Be True    1 <= int('${time}[2]') <= 31
     Should Be True    0 <= int('${time}[3]') <= 23
     Should Be True    0 <= int('${time}[4]') <= 59
     Should Be True    0 <= int('${time}[5]') <= 59
     ${year}    ${min}    ${sec} =    Get Time    seconds and minutes and year and whatnot
-    Should Be True    2000 < ${year} < 2100
+    Should Match Regexp    ${year}    \\d{4}
     Should Be True    0 <= int('${min}') <= 59
     Should Be True    0 <= int('${sec}') <= 59
 
diff --git a/atest/testdata/standard_libraries/operating_system/modified_time.robot b/atest/testdata/standard_libraries/operating_system/modified_time.robot
index 9489b3c9c..c712ebaed 100644
--- a/atest/testdata/standard_libraries/operating_system/modified_time.robot
+++ b/atest/testdata/standard_libraries/operating_system/modified_time.robot
@@ -14,13 +14,13 @@ Get Modified Time As Timestamp
 
 Get Modified Time As Seconds After Epoch
     ${dirtime} =    Get Modified Time    ${CURDIR}    epoch
-    Should Be True    1000000000 < ${dirtime} < 2000000000
+    Should Be True    ${dirtime} > 0
     ${current} =    Get Time    epoch
     Should Be True    ${current} >= ${dirtime}
 
 Get Modified Time As Parts
     ${year} =    Get Modified Time    ${CURDIR}    year
-    Should Be True    2000 < ${year} < 2100
+    Should Match Regexp    ${year}    \\d{4}
     ${yyyy}    ${mm}    ${dd} =    Get Modified Time    ${CURDIR}    year, month, day
     Should Be Equal    ${yyyy}    ${year}
     # Must use `int('x')` because otherwise 08 and 09 are considered octal
cal.mk (MODULES_NOT_COMPILED): ... here.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-08-02 15:48:59 -0400'>2021-08-02</span></td><td><a href='/guix/commit/gnu/tests/data?id=4673f817938d9d2b1b40a072ab2e0c44a32ccc97'>Revert "services: Add a service for Jami."</a><span class='msg-avail'>...<span class='msg-tooltip'>This reverts commit 69dcc24c9f0cdfea674eb690e7755d26a25ced2b.  It broke 'guix
pull'.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-08-02 15:15:02 -0400'>2021-08-02</span></td><td><a href='/guix/commit/gnu/tests/data?id=69dcc24c9f0cdfea674eb690e7755d26a25ced2b'>services: Add a service for Jami.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/telephony.scm (string-or-computed-file?)
(string-list?, account-fingerprint-list?): New procedures.
(maybe-string-list, maybe-account-fingerprint-list)
(maybe-boolean, maybe-string, jami-account-list): New configuration field
types.
(serialize-string-list, serialize-boolean, serialize-string)
(jami-account, jami-account-&gt;alist, jami-configuration)
(jami-account-list?, jami-account-list-maybe): New procedures.
(%jami-accounts): New variable.
(jami-configuration-&gt;command-line-arguments): New procedure.
(jami-dbus-session-activation, jami-shepherd-services): New procedures.
(jami-service-type): New variable.
* gnu/build/jami-service.scm: New file.
* gnu/tests/data/jami-dummy-account.dat: Likewise.
* gnu/tests/telephony.scm: Likewise.
* gnu/local.mk (GNU_SYSTEM_MODULES): Register them.
* Makefile.am (SCM_TESTS): Register the test file.
(dist_patch_DATA): Register the new data file.
* doc/guix.texi (Telephony Services): Document it.
</span></span></td><td>Maxim Cournoyer</td></tr>